@article{uzsoy_2024, title={Editorial}, url={https://doi.org/10.1109/TSM.2024.3355574}, DOI={10.1109/TSM.2024.3355574}, abstractNote={As we enter a New Year, we can look back on another year of solid accomplishment at IEEE Transactions on Semiconductor Manufacturing. I am happy to report that our impact factor remains steady at 2.70, and our mean time to first decision remains competitive at 8.3 weeks. Our Editorial Board remains as strong as ever, with the addition of Dr. Jun-Haeng Lee in the area of machine learning and data science applications in 2023, and we are actively seeking new board members. Our submissions remain strong, as do the special sections from conferences (ASMC, ISSM and CS-MANTECH). The Special Issue on Production-Level Artificial Intelligence Applications in Semiconductor Manufacturing appeared in the November issue, and two additional special issues are in preparation. Prof. Duane Boning of MIT and Dr. Bill Nehrer of Technology Consultancy are co-editing a special issue on “Semiconductor Design for Manufacturing,” which will be a collaborative effort with the IEEE Transactions on Electron Devices. Drs. Oliver Patterson of Intel and Tomasz Brozek of PDF Solutions are also co-editing a special issue on sustainable semiconductor manufacturing. We are also happy to announce the Best paper Award for 2023, in the companion editorial appearing in this issue. Congratulations to all the honorees, and we hope we will continue to see their submissions in the future. Our thanks go to Drs. Jeanne Bickford, Dragan Djurdjanovic and Mahadeva Iyer Natarajan for their work on this committee.}, journal={IEEE Transactions on Semiconductor Manufacturing}, author={Uzsoy, Reha}, year={2024}, month={Feb} }
 @article{uzsoy_2023, title={The Editorial}, volume={36}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2023.3267283}, DOI={10.1109/TSM.2023.3267283}, abstractNote={As we publish our second issue of the year, the IEEE Transactions on Semiconductor Manufacturing (TSM) team continues to evolve in new and interesting directions. We welcome three new members to our Steering Committee: Dr. Charles Recchia of Waters Corporation, representing the Reliability Society, Dr. Tomasz Brozek of PDF Solutions, representing the Electron Devices Society, and Dr. Bill Nehrer, also representing the EDS. I would like to extend my sincere thanks, on behalf of the entire TSM community, to our departing Steering Committee members, Drs. John Dallesasse, Simon Deleonibus, and Steven Li. I am especially grateful to Dr. Dallesasse, long-serving Chair of the Steering Committee, for his constant support and mentoring as I learned the job of Editor-in-Chief over the last five years. Dr. Peter Magnee, representing the Solid State Circuits Council, takes over as Steering Committee Chair, and Dr. Recchia as Treasurer.}, number={2}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Uzsoy, Reha}, year={2023}, month={May}, pages={157–157} }
 @article{bansal_ozaltin_uzsoy_kempf_2022, title={Coordination of manufacturing and engineering activities during product transitions}, volume={4}, ISSN={["1520-6750"]}, DOI={10.1002/nav.22056}, abstractNote={Abstract}, journal={NAVAL RESEARCH LOGISTICS}, author={Bansal, Ankit and Ozaltin, Osman Y. and Uzsoy, Reha and Kempf, Karl G.}, year={2022}, month={Apr} }
 @article{uzsoy_2022, title={Editorial}, volume={35}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2022.3145545}, DOI={10.1109/TSM.2022.3145545}, abstractNote={As we enter 2022, we have some more changes to the TSM team to report. Ms. Rosemary Schreiber, our long-time staff administrator and the Transactions’ corporate memory, retired in December 2021 after 17 years with IEEE. Rosemary was our go-to person for anything associated with the journal, and both authors and editors will remember her unfailingly prompt, accurate and patient advice as she helped us all to get things done. The best wishes and gratitude of the TSM community go with her, and we all wish her and her family the best in this next stage of her career.}, number={1}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Uzsoy, Reha}, year={2022}, month={Feb}, pages={1–1} }
 @article{uzsoy_2022, title={Editorial}, volume={35}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2022.3162654}, DOI={10.1109/TSM.2022.3162654}, abstractNote={In this first Editorial of 2022, I am happy to welcome Dr. Martin Braun of Intel to our Editorial Board. Dr. Braun has a long record of distinguished accomplishments in the semiconductor industry with Texas Instruments and Intel in a variety of roles. He brings to TSM his expertise in advanced process control, data analytics and factory and supply chain management. We look forward to working with him these coming years.}, number={2}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Uzsoy, Reha}, year={2022}, month={May}, pages={153–153} }
 @article{uzsoy_2022, title={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING Editorial}, volume={35}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2022.3213385}, DOI={10.1109/TSM.2022.3213385}, abstractNote={As 2022 draws to a close, I recently had the pleasant task of updating our Steering Committee on TSM’s situation at the end of another year. Our impact factor for 2021, the most recent data available, remains high, at 2.795, comparable to that of journals handling a much larger volume of papers than ours. This is a significant improvement from 1.18 in 2018, and one for which the entire TSM community—the staff, the Editorial Board, the reviewers, but especially the authors—should feel justifiably proud. Our financial situation is strong, our page count is growing, and our mean time to first review remains below ten weeks. We must continue to maintain and improve our performance, but we can look back on a year of solid progress.}, number={4}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Uzsoy, Reha}, year={2022}, month={Nov}, pages={595–595} }
 @article{ghadimi_aouam_haeussler_uzsoy_2022, title={Integrated and hierarchical systems for coordinating order acceptance and release planning}, volume={303}, ISSN={["1872-6860"]}, DOI={10.1016/j.ejor.2022.03.057}, abstractNote={We present hierarchical models for coordinating order acceptance and release planning under load-dependent lead times. Our integrated models use detailed information at the item level, while the hierarchical models decompose the decision process into order acceptance and order release subproblems that are solved sequentially. Demand uncertainty is addressed by implementing the proposed models in a rolling horizon framework, and by including chance-constraints that include safety stock to address demand uncertainty. Simulation experiments show that the hierarchical models can capture almost all of the benefit of coordinated order acceptance and release and require less computational effort. The chance-constrained models that build safety stocks are effective in the face of uncertain order quantities.}, number={3}, journal={EUROPEAN JOURNAL OF OPERATIONAL RESEARCH}, author={Ghadimi, Foad and Aouam, Tarik and Haeussler, Stefan and Uzsoy, Reha}, year={2022}, month={Dec}, pages={1277–1289} }
 @article{khorramfar_ozaltin_kempf_uzsoy_2022, title={Managing Product Transitions: A Bilevel Programming Approach}, volume={6}, ISSN={["1526-5528"]}, url={https://doi.org/10.1287/ijoc.2022.1210}, DOI={10.1287/ijoc.2022.1210}, abstractNote={ We model the hierarchical and decentralized nature of product transitions using a mixed-integer bilevel program with two followers, a manufacturing unit and an engineering unit. The leader, corporate management, seeks to maximize revenue over a finite planning horizon. The manufacturing unit uses factory capacity to satisfy the demand for current products. The demand for new products, however, cannot be fulfilled until the engineering unit completes their development, which, in turn, requires factory capacity for prototype fabrication. We model this interdependency between the engineering and manufacturing units as a generalized Nash equilibrium game at the lower level of the proposed bilevel model. We present a reformulation where the interdependency between the followers is resolved through the leader’s coordination, and we derive a solution method based on constraint and column generation. Our computational experiments show that the proposed approach can solve realistic instances to optimality in a reasonable time. We provide managerial insights into how the allocation of decision authority between corporate leadership and functional units affects the objective function performance. This paper presents the first exact solution algorithm to mixed-integer bilevel programs with interdependent followers, providing a flexible framework to study decentralized, hierarchical decision-making problems. }, journal={INFORMS JOURNAL ON COMPUTING}, author={Khorramfar, Rahman and Ozaltin, Osman Y. and Kempf, Karl G. and Uzsoy, Reha}, year={2022}, month={Jun}, pages={1–17} }
 @article{ghadimi_aouam_uzsoy_2022, title={Safety stock placement with market selection under load-dependent lead times}, volume={5}, ISSN={["2472-5862"]}, url={https://doi.org/10.1080/24725854.2022.2074578}, DOI={10.1080/24725854.2022.2074578}, abstractNote={Abstract We study the problem of safety stock placement in a supply chain with market selection decisions. A manufacturer with deterministic, load-dependent lead time supplies multiple warehouses, each serving multiple retailers. Each retailer has access to a set of potential markets with different characteristics. Serving more markets increases revenues, but also increases the manufacturer’s lead time, resulting in higher inventory costs. Adopting the Guaranteed Service Approach, we present a nonlinear mixed-integer programming model and reformulate it to eliminate integer variables related to service times at warehouses. We then propose a successive piecewise linearization algorithm and a mixed-integer conic quadratic formulation to solve the resulting nonlinear binary formulation. Computational experiments show that the successive piecewise linearization algorithm outperforms two state-of-the-art solvers, BARON and CPLEX, which are used to solve instances of the original formulation and the mixed-integer conic quadratic reformulation, respectively. The value of incorporating load-dependent lead times is greatest when capacity is limited relative to available demand. The benefit of integrating market selection and safety stock decisions is greatest when capacity is limited and marginal revenue is relatively low.}, journal={IISE TRANSACTIONS}, publisher={Informa UK Limited}, author={Ghadimi, Foad and Aouam, Tarik and Uzsoy, Reha}, year={2022}, month={May} }
 @article{ghademi_aouam_uzsoy_2022, title={Safety stock placement with market selection under load-dependent lead times}, volume={3}, DOI={/10.1080/24725854.2022.2074578}, abstractNote={We study the problem of safety stock placement in a supply chain with market selection decisions. A manufacturer with deterministic, load-dependent lead time supplies multiple warehouses, each serving multiple retailers. Each retailer has access to a set of potential markets with different characteristics. Serving more markets increases revenues, but also increases the manufacturer’s lead time, resulting in higher inventory costs. Adopting the Guaranteed Service Approach, we present a nonlinear mixed-integer programming model and reformulate it to eliminate integer variables related to service times at warehouses. We then propose a successive piecewise linearization algorithm and a mixed-integer conic quadratic formulation to solve the resulting nonlinear binary formulation. Computational experiments show that the successive piecewise linearization algorithm outperforms two state-of-the-art solvers, BARON and CPLEX, which are used to solve instances of the original formulation and the mixed-integer conic quadratic reformulation, respectively. The value of incorporating load-dependent lead times is greatest when capacity is limited relative to available demand. The benefit of integrating market selection and safety stock decisions is greatest when capacity is limited and marginal revenue is relatively low.}, journal={IISE Transactions on Scheduling and Logistics}, author={Ghademi, F. and Aouam, T. and Uzsoy, R.}, year={2022}, month={Mar} }
 @article{leca_kempf_uzsoy_2022, title={TOWARDS DECENTRALIZED DECISIONS FOR MANAGING PRODUCT TRANSITIONS IN SEMICONDUCTOR MANUFACTURING}, ISSN={["0891-7736"]}, DOI={10.1109/WSC57314.2022.10015337}, abstractNote={Continuous renewal of the product portfolio through product transitions is crucial to semiconductor manufacturing firms. These decisions take place in a decentralized environment, where decisions by different functional units must be coordinated to optimize corporate performance. Starting from a centralized optimization model, we obtain decentralized models using Lagrangian relaxation, and explore the challenges encountered in formulating and solving these decentralized models. Although the Lagrangian approaches yield tight upper bounds on the optimal solution value, the structure of the dual solution renders the construction of a near-optimal feasible solution difficult, and fully separable decentralized models encounter significant problems in achieving convergence due to scaling issues. We present computational experiments that illustrate the difficulties involved, and discuss directions for future work.}, journal={2022 WINTER SIMULATION CONFERENCE (WSC)}, author={Leca, Carlos and Kempf, Karl and Uzsoy, Reha}, year={2022}, pages={3442–3452} }
 @article{sutterer_kolisch_uzsoy_2022, title={Valuation of hospital resources: an optimization approach using clearing functions}, volume={4}, url={https://doi.org/10.1080/24725579.2022.2055236}, DOI={10.1080/24725579.2022.2055236}, abstractNote={Abstract We propose an approach to estimating the time-dependent marginal values of hospital resources facing heterogeneous patient demand over time using the dual variables of a novel dynamic patient admission and flow planning model maximizing hospital revenue. Clearing functions are used to represent the queuing behavior of the patients within the hospital. Using a large data set containing 17,483 patients treated over one year in a 400-bed hospital, we undertake a computational study where we derive the value of hospital resources under different demand and resource scenarios. Our results show that large instances of the model can be solved in reasonable CPU times, and that the model yields resource valuations that are qualitatively different from conventional approaches ignoring queueing costs.}, journal={IISE Transactions on Healthcare Systems Engineering}, author={Sutterer, P. and Kolisch, R. and Uzsoy, R.}, year={2022}, month={Apr} }
 @inproceedings{leca_kempf_uzsoy_2021, title={A Resource Coordination Model for Managing Product Transitions}, author={Leca, C.A. and Kempf, K.G. and Uzsoy, R.}, year={2021}, month={Aug} }
 @article{kapadia_uzsoy_starly_warsing_2021, title={A genetic algorithm for order acceptance and scheduling in additive manufacturing}, volume={10}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2021.1991023}, abstractNote={ABSTRACT We consider the problem of order acceptance and scheduling faced by an additive manufacturing facility consisting of multiple build chambers and postprocessing operations for support removal and surface finishing. We model each build chamber as a batch processing machine with processing times determined by the nesting and orientation of parts within the chamber. Due to the difficulty of developing an explicit functional relation between part batching, batch processing time, and postprocessing requirements we develop random-keys based genetic algorithms to select orders for complete or partial acceptance and produce a high-quality schedule satisfying all technological constraints, including part orientation and rotation within the build chamber. Extensive computational experiments show that the proposed approaches yield significant improvements in profit over the situation where all orders must be accepted, and produce solutions that compare favourably to statistically estimated bounds.}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Kapadia, Maaz Saleem and Uzsoy, Reha and Starly, Binil and Warsing, Donald P., Jr.}, year={2021}, month={Oct} }
 @misc{leca_kempf_uzsoy_2021, title={An Optimization Framework for Managing Product Transitions in Semiconductor Manufacturing}, url={http://dx.doi.org/10.1109/wsc52266.2021.9715390}, DOI={10.1109/wsc52266.2021.9715390}, abstractNote={The highly competitive nature of semiconductor manufacturing requires firms to constantly introduce new products with improved features and cost. Product divisions, which are responsible for product specification and demand forecasting, must collaborate with manufacturing and product engineering groups to develop new products and bring them into high-volume production for sale. We present a centralized optimization model for resource allocation across the different units. Computational experiments indicate that the model captures the interactions between agents in a logically consistent manner, providing a basis for decentralized approaches and stochastic formulations.}, journal={2021 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Leca, Carlos and Kempf, Karl and Uzsoy, Reha}, year={2021}, month={Dec} }
 @article{gopalswamy_uzsoy_2021, title={Conic programming models for production planning with clearing functions: Formulations and duality}, volume={292}, ISSN={0377-2217}, url={http://dx.doi.org/10.1016/j.ejor.2020.11.039}, DOI={10.1016/j.ejor.2020.11.039}, abstractNote={Concave clearing functions that model the expected throughput of a production resource as a function of its planned workload have yielded promising results when used in production planning models. The most common of these models take the form of linear programs (LPs) obtained by piecewise linearization of the clearing function constraints, leading to large formulations and inaccurate estimates of dual prices for resources. We show that several clearing function forms considered in the literature to date can be reformulated as conic programs (CPs), for which efficient solution methods and an elegant duality theory analogous to that for linear programming exist. We derive expressions for the optimal values of the dual variables and present computational experiments showing that the dual prices obtained from the CP formulation are more accurate than those obtained from the piecewise linearized LP models. In addition, the CP solution outperforms the LP solutions with respect to nervousness.}, number={3}, journal={European Journal of Operational Research}, publisher={Elsevier BV}, author={Gopalswamy, Karthick and Uzsoy, Reha}, year={2021}, month={Aug}, pages={953–966} }
 @article{bansal_uzsoy_2021, title={Constraint violation reduction search for 0-1 mixed integer linear programming problems}, volume={53}, ISSN={["1029-0273"]}, DOI={10.1080/0305215X.2020.1742710}, abstractNote={This article presents Constraint Violation Reduction Search (CVRS), a primal heuristic for 0–1 Mixed Integer Linear Programming (MILP) problems. CVRS constructs a series of MILP subproblems by adding artificial variables representing the amount by which each constraint is violated and minimizing their sum in the objective function. A cutoff constraint added to each subproblem ensures that the objective function value of the original MILP problem improves at each iteration. If no integer feasible solution to the MILP subproblem can be found, a neighbourhood search is used to repair the infeasibility. CVRS is tested on 99 hard instances of resource constrained project scheduling, Mixed Integer Programming Library (MIPLIB) and capacitated warehouse location, and its performance is compared to a recent neighbourhood search based primal heuristic for MILP and the CPLEX MILP solver with promising results.}, number={4}, journal={ENGINEERING OPTIMIZATION}, author={Bansal, Ankit and Uzsoy, Reha}, year={2021}, month={Apr}, pages={609–626} }
 @article{uzsoy_2021, title={Editorial}, volume={34}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2021.3073760}, DOI={10.1109/TSM.2021.3073760}, abstractNote={One of the most pleasant aspects of the Editor in Chief’s job is to recognize outstanding contributions from the TSM community. The TSM Best Paper Award is presented annually to a paper published in the previous calendar year that is recognized by the Editorial Board to have made an outstanding contribution to the field. Papers are nominated at the time of acceptance by the handling Associate Editor; nominated papers are then reviewed and ranked by a subcommittee of the Editorial Board.}, number={2}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Uzsoy, Reha}, year={2021}, month={May}, pages={139–139} }
 @article{uzsoy_2021, title={Editorial}, volume={34}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2021.3119086}, DOI={10.1109/TSM.2021.3119086}, abstractNote={As another year draws to a close, TSM can look back on a busy but successful year. In February 2021 we underwent our five-yearly review by IEEE’s Publications Review and Advisory Committee (PRAC), and I am happy to say that we passed with flying colors. The reviewers made several excellent suggestions for further improvement, including conducting a survey of our readers and authors to assess their satisfaction with the current state of TSM and receive their input for the future. We have already begun acting on these suggestions, and I will keep the community informed as they develop.}, number={4}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Uzsoy, Reha}, year={2021}, month={Nov}, pages={443–443} }
 @misc{uzsoy_2021, title={Fast Approximate Solutions for Capacitated Production Planning Under Uncertain Demand}, author={Uzsoy, R.}, year={2021}, month={Jan} }
 @article{manda_uzsoy_2021, title={Managing product transitions with learning and congestion effects}, volume={239}, ISSN={["1873-7579"]}, DOI={10.1016/j.ijpe.2021.108190}, abstractNote={The introduction of a new product into an operating factory can have significant adverse impacts on the throughput and cycle time of all products produced in the factory, and thus needs to be managed carefully. In previous work we proposed a production planning model for new product introductions that captures the impact of additional variability caused by the new product and of learning as experience producing the new product is gained. This paper extends the earlier work by incorporating learning through deliberate experimentation using engineering lots and the impact of cycle time on line yield due to delays in detecting adverse events. We formulate a non-convex nonlinear optimization model to determine the mix of production and engineering lots to be processed, and obtain approximate solutions using a genetic algorithm. Numerical experiments with different scenarios show the importance of carefully managing the releases of production and engineering lots and of accelerating learning early in the time horizon through judicious use of engineering lots.}, journal={INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS}, author={Manda, A. B. and Uzsoy, Reha}, year={2021}, month={Sep} }
 @article{missbauer_uzsoy_2021, title={Order release in production planning and control systems: challenges and opportunities}, volume={11}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2021.1994165}, abstractNote={Production planning and control (PPC) systems are important to the competitiveness of manufacturing firms and their ability to benefit from recent technological advances. We give an overview of research and unsolved research questions in PPC systems related to the order release function that sets output targets for autonomous production units that manage production at the shop-floor level. We describe the hierarchical Manufacturing Planning and Control (MPC) and Advanced Planning and Scheduling (APS) architectures for PPC systems prevalent in practice and the positioning of the order release task within these frameworks. We then describe the research streams relevant to order release, optimisation models for order release planning, and the relation of these models to the overall PPC system. Modelling the dynamic response of production units to time-varying work input, which represents an extension of classical production theory by incorporating the time dimension, is identified as the major modelling challenge. We conclude by suggesting several unsolved research questions that should encourage researchers to work on this topic which is far from mature.}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Missbauer, Hubert and Uzsoy, Reha}, year={2021}, month={Nov} }
 @inproceedings{albey_kempf_uzsoy_2020, title={A Lagrangian Approach for Stochastic Multiproduct Production Planning with Forecast Evolution}, booktitle={Proceedings of the International Working Seminar on Production Economics}, author={Albey, E. and Kempf, K.G. and Uzsoy, R.}, year={2020}, month={Feb} }
 @article{manda_gopalswamy_shashaani_uzsoy_2020, title={A SIMULATION OPTIMIZATION APPROACH FOR MANAGING PRODUCT TRANSITIONS IN MULTISTAGE PRODUCTION LINES}, ISSN={["0891-7736"]}, url={http://dx.doi.org/10.1109/wsc48552.2020.9384036}, DOI={10.1109/WSC48552.2020.9384036}, abstractNote={We explore the problem of managing releases into a multistage production system transitioning from producing a mature product in high volume to a new one whose production process is initially unreliable but improves as experience is accumulated. We use simulation optimization to develop solutions and examine the impact of learning at a single machine on the rest of the system. This work lays the foundation for studying product transitions using realistic fab scale simulation models.}, journal={2020 WINTER SIMULATION CONFERENCE (WSC)}, publisher={IEEE}, author={Manda, Atchyuta Bharadwaj and Gopalswamy, Karthick and Shashaani, Sara and Uzsoy, Reha}, year={2020}, pages={1730–1741} }
 @article{manda_uzsoy_2020, title={A Simple Model of Capacity Contention During New Product Introductions}, volume={33}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2020.2981412}, DOI={10.1109/TSM.2020.2981412}, abstractNote={We consider the problem of determining an optimal release schedule for a production facility as it transitions from producing an older product to a newer one. We use simple queueing ideas to model the impact of the new product introduction on the throughput rate and cycle time of both products. We then incorporate the learning gained from accumulated experience in producing the new product to formulate a deterministic optimization model for release planning during product transitions. Since the model is nonlinear and non-convex we use a genetic algorithm to obtain near-optimal solutions. The structure of the optimal solution provides insights into the relationships between the different costs involved in the model. Computational experiments show that the release planning model produces high-quality solutions in reasonable CPU times, and reflects the behavior of the system realistically. The principal insight is that careful management of releases during product transitions has the potential to mitigate many of the adverse effects frequently observed in practice such as longer cycle times for both old and new products.}, number={2}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Manda, Atchyuta Bharadwaj and Uzsoy, Reha}, year={2020}, month={May}, pages={240–251} }
 @article{uzsoy_2020, title={Editorial}, volume={33}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2020.2986873}, DOI={10.1109/TSM.2020.2986873}, abstractNote={The world is a rather different place now than it was last November, when I wrote the last of these editorials. As we deal with the worldwide economic slowdown, social distancing and the other consequences of the Covid-19 pandemic, I am grateful to all members of the TSM community who continue to work under trying conditions to keep the journal’s business going.}, number={2}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Uzsoy, Reha}, year={2020}, month={May}, pages={143–143} }
 @article{bansala_uzsoy_kempf_2020, title={Iterative combinatorial auctions for managing product transitions in semiconductor manufacturing}, volume={52}, ISSN={["2472-5862"]}, DOI={10.1080/24725854.2019.1651951}, abstractNote={Abstract Successful management of product transitions in the semiconductor industry requires effective coordination of manufacturing and product development activities. Manufacturing units must meet demand for current products while also allocating capacity to product development units for prototype fabrication that will support timely introduction of new products into high-volume manufacturing. Knowledge of detailed operational constraints and capabilities is only available within each unit, precluding the use of a centralized planning model with complete information of all units. However, the decision support tools used by the individual units offer the possibility of a decentralized decision framework that uses these local models as components to rapidly obtain mutually acceptable, implementable solutions. We develop Iterative Combinatorial Auctions (ICAs) that achieve coordinated decisions for all units to maximize the firm’s profit while motivating all units to share information truthfully. Computational results show that the ICA that uses column generation to update prices outperforms that using subgradient search, obtaining near-optimal corporate profit in low CPU times.}, number={4}, journal={IISE TRANSACTIONS}, author={Bansala, Ankit and Uzsoy, Reha and Kempf, Karl}, year={2020}, month={Apr}, pages={413–431} }
 @book{missbauer_uzsoy_2020, title={Production Planning with Capacitated Resources and Congestion}, ISBN={9781071603529 9781071603543}, url={http://dx.doi.org/10.1007/978-1-0716-0354-3}, DOI={10.1007/978-1-0716-0354-3}, publisher={Springer New York}, author={Missbauer, Hubert and Uzsoy, Reha}, year={2020} }
 @article{ziarnetzky_moench_uzsoy_2020, title={Simulation-Based Performance Assessment of Production Planning Models With Safety Stock and Forecast Evolution in Semiconductor Wafer Fabrication}, volume={33}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2019.2958526}, DOI={10.1109/TSM.2019.2958526}, abstractNote={We study the performance of production planning models for wafer fabs in a rolling horizon setting under stochastic demand modeled using the Martingale Model of Forecast Evolution (MMFE). The models differ in how they incorporate lead times and safety stocks. The number of frozen periods is considered as an experimental factor to study the nervousness of the resulting plans. Our simulation experiments show that chance-constrained production planning models that integrate safety stock and production planning decisions outperform others. The formulations with workload-dependent lead times also outperform those with fixed lead times that are an integer multiple of the period length.}, number={1}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Ziarnetzky, Timm and Moench, Lars and Uzsoy, Reha}, year={2020}, month={Feb}, pages={1–12} }
 @article{uzsoy_2019, title={2018 Best Paper Award}, volume={32}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2019.2910984}, DOI={10.1109/TSM.2019.2910984}, abstractNote={Each year the Transactions on Semiconductor Manufacturing recognizes the best paper published during the previous calendar year. This year 12 papers were nominated by our reviewers and members of our Editorial Board and Steering Committee. The paper entitled “Maximizing Output During Ramp by Integrating Capacity and Velocity” by Adar A. Kalir and Kosta Rozen of Intel Corporation (vol. 31, no. 3, August 2018) was recognized as the Best Paper of 2018. The authors examine the very important problem of managing starts into a wafer fab during the ramp-up of new capacity, and find that maintaining starts slightly below constraint capacity to reduce cycle times can actually increase total output over the ramp-up duration.}, number={2}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Uzsoy, Reha}, year={2019}, month={May}, pages={139–139} }
 @misc{albey_yanikoglu_uzsoy_2019, title={A Robust Optimization Approach for Production Planning Under Exogenous Planned Lead Times}, url={http://dx.doi.org/10.1109/wsc40007.2019.9004671}, DOI={10.1109/wsc40007.2019.9004671}, abstractNote={Many production planning models applied in semiconductor manufacturing represent lead times as fixed exogenous parameters. However, in reality, lead times must be treated as realizations of released lots’ cycle times, which are in fact random variables. In this paper, we present a distributionally robust release planning model that allows planned lead time probability estimates to vary over a specified ambiguity set. We evaluate the performance of non-robust and robust approaches using a simulation model of a scaled-down wafer fabrication facility. We examine the effect of increasing uncertainty in the estimated lead time parameters on the objective function value and compare the worst-case, average optimality, and feasibility of the two approaches. The numerical results show that the average objective function value of the robust solutions are better than that of the nominal solution by a margin of almost 20% in the scenario with the highest uncertainty level.}, journal={2019 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Albey, Erinc and Yanikoglu, Ihsan and Uzsoy, Reha}, year={2019}, month={Dec} }
 @article{gopalswamy_uzsoy_2019, title={A data-driven iterative refinement approach for estimating clearing functions from simulation models of production systems}, volume={57}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2018.1557351}, abstractNote={Clearing functions that describe the expected output of a production resource as a function of its expected workload have yielded promising production planning models. However, there is as yet no fully satisfactory approach to estimating clearing functions from data. We identify several issues that arise in estimating clearing functions such as sampling issues, systematic underestimation and model misspecification. We address the model misspecification problem by introducing a generalised functional form, and the sampling issues via iterative refinement of initial parameter estimates. The iterative refinement approach yields improved performance for planning models at higher levels of utilisation, and the generalised functional form results in significantly better production plans both alone and when combined with the iterative refinement approach. The IR approach also obtains solutions of similar quality to the much more computationally demanding simulation optimisation approaches used in previous work.}, number={19}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Gopalswamy, Karthick and Uzsoy, Reha}, year={2019}, month={Oct}, pages={6013–6030} }
 @article{kacar_moench_uzsoy_2019, title={A problem reduction approach for production planning using clearing functions}, volume={67}, ISSN={["0178-2312"]}, DOI={10.1515/auto-2018-0109}, abstractNote={Zusammenfassung}, number={6}, journal={AT-AUTOMATISIERUNGSTECHNIK}, author={Kacar, N. Baris and Moench, Lars and Uzsoy, Reha}, year={2019}, month={Jun}, pages={455–467} }
 @article{uzsoy_2019, title={Appreciation to the TSM Community}, volume={32}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2019.2946034}, DOI={10.1109/TSM.2019.2946034}, abstractNote={2019 has been a good year at TSM. Our 2017 Impact Factor was 1.35, representing another year of continuous increase since 2011. Over the course of this year, we have revised the Scope and Aims of the journal for the first time since its launch in 1988, in order to broaden the reach of the journal to manufacturing aspects of related areas such as photovoltaic devices and micro-electro-mechanical systems. I would encourage all of you review the new scope on IEEE Xplore.}, number={4}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Uzsoy, Reha}, year={2019}, month={Nov}, pages={362–362} }
 @misc{gopalswamy_uzsoy_2019, title={Conic Reformulation of Production Planning Models with Clearing Functions}, author={Gopalswamy, K. and Uzsoy, R.}, year={2019}, month={May} }
 @inproceedings{bansal_uzsoy_kempf_2019, place={Vancouver, BC, Canada}, title={Coordinating Capacity Negotiations in Semiconductor Manufacturing}, booktitle={Proceedings of the IEEE Conference on Automation Science and Engineering}, author={Bansal, A. and Uzsoy, R. and Kempf, K.G.}, year={2019}, month={Aug} }
 @misc{bluemink_de kok_srinivasan_uzsoy_2019, title={Evaluating Mixed Integer Programming Models for Solving Stochastic Inventory Problems}, url={http://dx.doi.org/10.1109/wsc40007.2019.9004920}, DOI={10.1109/wsc40007.2019.9004920}, abstractNote={We formulate mixed integer programming (MIP) models to obtain approximate solutions to finite horizon stochastic inventory models. These deterministic formulations of necessity make a number of simplifying assumptions, but their special structure permits very short model solution times under a range of experimental conditions. We evaluate the performance of these models using simulation optimization to estimate the true optimal solutions. Computational experiments identify several demand and cost scenarios in which the MIP models yield near-optimal solutions, and other cases where they fail, suggesting directions for future research.}, journal={2019 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Bluemink, Bas and de Kok, A. G. and Srinivasan, Balan and Uzsoy, Reha}, year={2019}, month={Dec} }
 @misc{kapadia_starly_thomas_uzsoy_warsing_2019, title={Impact of Part Scheduling Policy on Additive Manufacturing Production System Performance}, author={Kapadia, M.S. and Starly, B. and Thomas, A. and Uzsoy, R. and Warsing, D.}, year={2019}, month={May} }
 @article{kapadia_starly_thomas_uzsoy_warsing_2019, title={Impact of Scheduling Policies on the Performance of an Additive Manufacturing Production System}, volume={39}, ISSN={2351-9789}, url={http://dx.doi.org/10.1016/j.promfg.2020.01.388}, DOI={10.1016/j.promfg.2020.01.388}, abstractNote={We study the impact of scheduling policies on the cycle time and throughput of an Additive Manufacturing (AM) facility. Orders for irregularly shaped parts with specified due dates and surface quality requirements arrive randomly at the facility. The parts are fabricated in one of several AM build chambers, followed by post-processing operations based on surface finishing requirements. We combine a part placement heuristic with different scheduling policies (FIFO, Earliest Due Date) to allocate parts to AM build chambers and lay out the parts within the chambers to approximately optimize delivery performance. Simulation experiments using an Iterative Optimization-based Simulation (IOS) model integrating a simulation engine (implemented in SIMIO) with a computational engine (implemented in MATLAB) show that the scheduling policies have a significant impact on cycle time and order lateness. Selection and peer review under the responsibility of ICPR25 International Scientific & Advisory and Organizing Committee members.}, journal={Procedia Manufacturing}, publisher={Elsevier BV}, author={Kapadia, Maaz Saleem and Starly, Binil and Thomas, Alec and Uzsoy, Reha and Warsing, Donald}, year={2019}, pages={447–456} }
 @inproceedings{kapadia_starly_thomas_uzsoy_warsing_2019, title={Impact of Scheduling Policies on the Performance of an Additive Manufacturing System}, author={Kapadia, M.S. and Starly, B. and Thomas, A. and Uzsoy, R. and Warsing, D.}, year={2019}, month={Aug} }
 @misc{manda_uzsoy_2019, title={Optimzing Engineering and Production Lots During Product Transitions in Semiconductor Manufacturing}, url={http://dx.doi.org/10.1109/wsc40007.2019.9004879}, DOI={10.1109/wsc40007.2019.9004879}, abstractNote={The adverse impact of new product introductions on the performance of semiconductor wafer fabrication facilities (fabs) is widely acknowledged. In this paper, we develop a simulation model of a simplified production system that captures the impact of a new product introduction and the learning effects of production and engineering activities on the total system throughput. We use a simulation optimization procedure utilizing a Genetic Algorithm (GA) to obtain near optimal releases of production and engineering lots that maximize total contribution over the planning horizon. Numerical experiments provide insights into the structure of optimal release policies and illustrate the improvements that can be achieved through the strategic use of engineering lots.}, journal={2019 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Manda, Atchyuta Bharadwaj and Uzsoy, Reha}, year={2019}, month={Dec} }
 @misc{manda_uzsoy_2019, title={Simulation Optimization For Planning Product Transitions In Semiconductor Manufacturing Facilities}, author={Manda, A.B. and Uzsoy, R.}, year={2019}, month={May} }
 @article{gopalswamy_fathi_uzsoy_2019, title={Valid inequalities for concave piecewise linear regression}, volume={47}, ISSN={["1872-7468"]}, DOI={10.1016/j.orl.2018.12.004}, abstractNote={Abstract We consider the problem of fitting a concave piecewise linear function to multivariate data using the Least Absolute Deviation objective. We propose new valid inequalities for the problem using the properties of concave functions. Results with univariate data show that the proposed valid inequalities improve the root relaxation lower bound, permitting significant improvements in solution time.}, number={1}, journal={OPERATIONS RESEARCH LETTERS}, author={Gopalswamy, Karthick and Fathi, Yahya and Uzsoy, Reha}, year={2019}, month={Jan}, pages={52–58} }
 @misc{manda_uzsoy_2018, title={A Review of Product Ramping Models in Semiconductor Manufacturing}, author={Manda, A.B. and Uzsoy, R.}, year={2018}, month={Nov} }
 @article{karagul_warsing_hodgson_kapadia_uzsoy_2018, title={A comparison of mixed integer programming formulations of the capacitated lot-sizing problem}, volume={56}, ISSN={["1366-588X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85035114913&partnerID=MN8TOARS}, DOI={10.1080/00207543.2017.1401232}, abstractNote={We propose a novel mixed integer programming formulation for the capacitated lot-sizing problem with set-up times and set-up carryover. We compare our formulation to two earlier formulations, the Classical and Modified formulations, and a more recent formulation due to Suerie and Stadtler. Extensive computational experiments show that our formulation consistently outperforms the Classical and Modified formulations in terms of CPU time and solution quality. It is competitive with the Suerie–Stadtler (S&S) formulation, but outperforms all other formulations on the most challenging instances, those with low-capacity slack and a dense jobs matrix. We show that some of the differences in the performance of these various formulations arise from their different use of binary variables to represent production or set-up states. We also show that the LP relaxation of our Novel formulation provides a tighter lower bound than that of the Modified formulation. Our experiments demonstrate that, while the S&S formulation provides a much tighter LP bound, the Novel formulation is better able to exploit the intelligence of the CPLEX solution engine.}, number={23}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Karagul, Hakan F. and Warsing, Donald P. and Hodgson, Thom J. and Kapadia, Maaz S. and Uzsoy, Reha}, year={2018}, pages={7064–7084} }
 @article{uzsoy_fowler_mönch_2018, title={A survey of semiconductor supply chain models Part II: demand planning, inventory management, and capacity planning}, volume={56}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207543.2018.1424363}, DOI={10.1080/00207543.2018.1424363}, abstractNote={Part I of this three-part series described semiconductor supply chains from the decision-making and functional perspectives, using this as a framework to review the industrial engineering and operations research literature on the problems arising in these supply chains. Part I then reviewed the literature on Strategic Network Design, supply chain coordination, sustainability and simulation-based decision support. This paper, Part II, reviews the areas of Demand Planning, Inventory Management and Capacity Planning in semiconductor supply chains. Part III concludes the series by discussing models to support Master Planning, Production Planning and Demand Fulfilment in this industry.}, number={13}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Uzsoy, Reha and Fowler, John W. and Mönch, Lars}, year={2018}, month={Feb}, pages={4546–4564} }
 @misc{gopalswamy_uzsoy_2018, title={AN EXPLORATORY COMPARISON OF CLEARING FUNCTION AND DATA-DRIVEN PRODUCTION PLANNING MODELS}, url={http://dx.doi.org/10.1109/wsc.2018.8632371}, DOI={10.1109/wsc.2018.8632371}, abstractNote={Production planning models face the fundamental problem of capturing the nonlinear relation between resource workload and cycle times. One approach to this has been the use of nonlinear clearing functions that represent the expected output of a production resource in a planning period as a function of the expected workload in that period. Recently an alternative data driven approach that represents the behavior of the system using a set of system states and their corresponding output levels has been proposed. We compare the clearing function based approach to the data driven approach using a simulation model of a scaled-down semiconductor wafer fabrication facility and discuss the strengths and weaknesses of the two approaches.}, journal={2018 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Gopalswamy, Karthick and Uzsoy, Reha}, year={2018}, month={Dec} }
 @article{uzsoy_2018, title={Appreciation to Our Reviewers}, volume={31}, ISSN={["1558-2345"]}, DOI={10.1109/TSM.2018.2871481}, abstractNote={Each year it is the privilege and responsibility of the Editor-in-Chief to acknowledge the reviewers whose largely anonymous efforts lie at the heart of any scientific publication, and the communities of scholars and practitioners whom it serves. As such, it is worth taking a few minutes to reflect on the purpose of the peer review process, and the contributions our reviewers make. To my mind the principal purposes of peer review are to determine whether the paper merits publication, and to help authors write better papers.}, number={4}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Uzsoy, Reita}, year={2018}, month={Nov}, pages={405–405} }
 @misc{gopalswamy_uzsoy_2018, title={Conic Reformulations of Production Planning Problems with Clearing Functions}, author={Gopalswamy, K. and Uzsoy, R.}, year={2018}, month={Nov} }
 @inproceedings{bansal_uzsoy_kempf_2018, title={Coordinating Capacity Negotiations In Semiconductor Industry}, author={Bansal, A. and Uzsoy, R. and Kempf, K.G.}, year={2018}, month={Nov} }
 @article{uzsoy_2018, title={Editorial 2017 Best Paper Award}, volume={31}, url={https://doi.org/10.1109/TSM.2018.2852818}, DOI={10.1109/TSM.2018.2852818}, abstractNote={Each year the Transactions on Semiconductor Manufacturing recognizes the best paper published during the previous calendar year. This year 9 papers were nominated by our reviewers and members of our Editorial Board and Steering Committee, out of a total of 78 papers published in our pages in 2017. From among these, the members of the Editorial Board and Steering Committee selected the paper entitled “A Novel Dynamic Process Control Scheme to Improve Cycle Time in Fabs” by Dr. Michael Hassoun of the Department of Industrial Engineering and Management of Ariel University in Israel. This paper continues an ongoing line of research examining the impact of process control policies on the tradeoff between cycle time and yield in wafer fabrication. The primary finding is that modest relaxation of process control parameters to reduce time spent adjusting production equipment when it is in high demand can often reduce cycle time with minimal negative impact. A number of fruitful extensions for future work are also discussed, holding out the possibility of improved integration of scheduling and process control techniques. On behalf of the TSM community, I have the pleasure of congratulating Dr. Hassoun on this recognition, and of wishing him continued success in future.}, number={3}, journal={IEEE Transactions on Semiconductor Manufacturing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Uzsoy, Reha}, year={2018}, month={Aug}, pages={325–325} }
 @article{uzsoy_2018, title={Editorial from the Incoming Editor-in-Chief}, volume={31}, ISSN={["1558-2345"]}, url={https://doi.org/10.1109/TSM.2018.2820239}, DOI={10.1109/tsm.2018.2820239}, abstractNote={I am delighted to have the opportunity to serve as Editor-in-Chief of this prestigious transactions. I am very grateful to Prof. Anthony Muscat, the outgoing Editor-in-Chief, for bringing the opportunity to my attention and for his advice and support during the transition, as well as Jim Skowrenski of IEEE - EDS and the members of the Steering Committee who offered me the opportunity. I would also like to thank Marlene James, Rosemary Schreiber and Margaret Rafferty of IEEE Publications for their assistance as I learn the ropes. It is the collective efforts of this outstanding team that has brought the transactions to its current level.}, number={2}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Uzsoy, Reha}, year={2018}, month={May}, pages={195–195} }
 @inproceedings{sengul orgut_ivy_uzsoy_2018, title={Modeling for the Equitable and Effective Distribution of Food Donations Under Stochastic Capacities}, author={Sengul Orgut, I. and Ivy, J.S. and Uzsoy, R.}, year={2018}, month={Nov} }
 @misc{manda_uzsoy_2018, title={Planning Releases During Product Transitions in Semiconductor Manufacturing}, author={Manda, A.B. and Uzsoy, R.}, year={2018}, month={Nov} }
 @misc{kacar_munch_uzsoy_2018, title={Problem Reduction Approaches for Production Planning Using Clearing Functions}, url={http://dx.doi.org/10.1109/coase.2018.8560429}, DOI={10.1109/coase.2018.8560429}, abstractNote={A limitation of many mathematical programming models for production planning is their inability to reflect the nonlinear relation between workload and cycle times. Nonlinear clearing functions (CFs) explicitly model this relationship, and have shown promise for developing effective formulations. However, the use of CFs results in much larger models, and the effort involved in estimating the CFs is also significant. This paper examines the performance of reduced models where only a subset of potentially critical workcenters is represented with CFs. We find that even when the workcenters considered involve 75% of the average work in progress (WIP) in the system, the reduced models result in substantially lower performance than the full model where CFs are fitted to all workcenters. These results suggest that interactions between workcenters are quite complex and that models focusing on a limited set of machines may give misleading estimates of system performance. We provide insight into the causes of this behavior by analyzing the dual variables associated with the workcenters.}, journal={2018 IEEE 14th International Conference on Automation Science and Engineering (CASE)}, publisher={IEEE}, author={Kacar, N. Baris and Munch, Lars and Uzsoy, Reha}, year={2018}, month={Aug} }
 @inproceedings{ziarnetzky_monch_uzsoy_2018, title={Production Planning Models with Chance Constraints and Advance Demand Information}, author={Ziarnetzky, T. and Monch, L. and Uzsoy, R.}, year={2018}, month={May} }
 @article{medhin_uzsoy_2018, title={Production Planning and Engineering Process Improvement}, volume={22}, number={4}, journal={Communications in Applied Analysis}, author={Medhin, N. and Uzsoy, R.}, year={2018}, pages={583–596} }
 @inproceedings{sengul orgut_ivy_uzsoy_hale_2018, title={Robust Optimization Approaches for the Equitable and Effective Distribution of Donated Food}, author={Sengul Orgut, I. and Ivy, J.S. and Uzsoy, R. and Hale, C.}, year={2018}, month={Nov} }
 @article{orgut_ivy_uzsoy_hale_2018, title={Robust optimization approaches for the equitable and effective distribution of donated food}, volume={269}, ISSN={["1872-6860"]}, DOI={10.1016/j.ejor.2018.02.017}, abstractNote={Motivated by our eight-year partnership with a local food bank, we present two robust optimization models to support the equitable and effective distribution of donated food over the food bank's service area. Our first model addresses uncertainty in the amount of donated food counties can effectively receive and distribute, which depends on local factors such as budget and workforce that are unknown to the food bank. Assuming that the capacity of each county varies within a range, the model seeks to maximize total food distribution while enforcing a user-specified level of robustness. Our second model uses robust optimization in a nontraditional manner, treating the upper bound on the level of allowed inequity as an uncertain parameter and limiting total deviation from a perfectly equitable distribution over all counties while maximizing total food shipment. We derive structural properties of both models and develop efficient exact solution algorithms. We illustrate our models using historical data obtained from our food bank partner, summarize the policy implications of our results and examine the impact of uncertainty on outcomes and decision making.}, number={2}, journal={EUROPEAN JOURNAL OF OPERATIONAL RESEARCH}, author={Orgut, Irem Sengul and Ivy, Julie S. and Uzsoy, Reha and Hale, Charlie}, year={2018}, month={Sep}, pages={516–531} }
 @article{ziarnetzky_moench_uzsoy_2018, title={Rolling horizon, multi-product production planning with chance constraints and forecast evolution for wafer fabs}, volume={56}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2018.1478461}, abstractNote={In this paper, we study production planning models for semiconductor wafer fabrication facilities (wafer fabs) that consider both safety stocks at the finished goods inventory level and workload-dependent lead times. The evolution of demand forecasts over time follows the multiplicative Martingale Model of Forecast Evolution (MMFE) for multiple products and is incorporated into the planning models via shortfall-based chance constraints, permitting the simultaneous determination of production quantities and safety stocks. We study two variants of this formulation, one that considers forecast updates and one that does not. A planning model with workload-dependent lead times that does not consider safety stocks is used for comparison. The performance of the planning models is assessed in a rolling horizon environment using a simulation model of a scaled-down wafer fab. We find that the chance-constrained model with forecast updates outperforms the one without forecast updates with respect to expected service level and profit. Both chance-constrained models outperform the model without safety stocks. These results indicate that considering forecast evolution in production planning models can lead to improved performance by exploiting the advance demand information provided by the forecast updates.}, number={18}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Ziarnetzky, Timm and Moench, Lars and Uzsoy, Reha}, year={2018}, pages={6112–6134} }
 @article{kang_albey_uzsoy_2018, title={Rounding heuristics for multiple product dynamic lot-sizing in the presence of queueing behavior}, volume={100}, ISSN={["1873-765X"]}, url={https://doi.org/10.1016/j.cor.2018.07.019}, DOI={10.1016/j.cor.2018.07.019}, abstractNote={We present heuristics for solving a difficult nonlinear integer programming (NIP) model arising from a multi-item single machine dynamic lot-sizing problem. The heuristic obtains a local optimum for the continuous relaxation of the NIP model and rounds the resulting fractional solution to a feasible integer solution by solving a series of shortest path problems. We also implement two benchmarks: a version of the well-known Feasibility Pump heuristic and the Surrogate Method developed for stochastic discrete optimization problems. Computational experiments reveal that our shortest path based rounding procedure finds better production plans than the previously developed myopic heuristic and the benchmarks.}, journal={COMPUTERS & OPERATIONS RESEARCH}, author={Kang, Yongha and Albey, Erinc and Uzsoy, Reha}, year={2018}, month={Dec}, pages={54–65} }
 @misc{manda_uzsoy_2018, title={SIMULATION OPTIMIZATION FOR PLANNING PRODUCT TRANSITIONS IN SEMICONDUCTOR MANUFACTURING FACILITIES}, url={http://dx.doi.org/10.1109/wsc.2018.8632253}, DOI={10.1109/wsc.2018.8632253}, abstractNote={The introduction of a new product into a semiconductor manufacturing facility can have significant adverse effects on both current and new products. We combine a simulation model of a simplified production system and a learning model to optimize releases of old and new products using simulation optimization. Our results show that the simulation optimization model yields significant improvements in performance over simple alternatives, and provides insights into the structure of optimal release policies.}, journal={2018 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Manda, Atchyuta Bharadwaj and Uzsoy, Reha}, year={2018}, month={Dec} }
 @article{mönch_uzsoy_fowler_2017, title={A survey of semiconductor supply chain models part I: semiconductor supply chains, strategic network design, and supply chain simulation}, volume={56}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207543.2017.1401233}, DOI={10.1080/00207543.2017.1401233}, abstractNote={Supply chain management issues have become increasingly important to the semiconductor industry over the last two decades due to the global distribution of facilities and increasing numbers of firms specialising in particular stages. This series of three papers reviews the literature on modelling and analysis of the larger semiconductor supply chain. After describing the structure of semiconductor supply chains to provide context for the research efforts, we propose a classification scheme for the relevant literature. The remainder of this paper (Part I) then focuses on Strategic Network Design models for this industry, supply chain coordination through contracting and semiconductor supply chain simulation. Part II discusses Demand Planning, Inventory Management and Capacity Planning, while Part III addresses Master Planning, Production Planning and Demand Fulfilment.}, number={13}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Mönch, Lars and Uzsoy, Reha and Fowler, John W.}, year={2017}, month={Nov}, pages={4524–4545} }
 @article{mönch_uzsoy_fowler_2017, title={A survey of semiconductor supply chain models part III: master planning, production planning, and demand fulfilment}, volume={56}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207543.2017.1401234}, DOI={10.1080/00207543.2017.1401234}, abstractNote={Part I of this three-part series described semiconductor supply chains from the decision-making and functional perspectives, using this as a framework to review the industrial engineering (IE) and operations research (OR) literature on the problems arising in these supply chains. Part I then reviewed the literature on Strategic Network Design, Supply Chain Coordination, Sustainability and Semiconductor Supply Chain Simulation, while Part II reviewed Demand Planning, Inventory Management, and Capacity Planning. This paper concludes the series, discussing Master Planning, Production Planning, Demand Fulfilment, and Available to Promise (ATP) in semiconductor supply chains.}, number={13}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Mönch, Lars and Uzsoy, Reha and Fowler, John W.}, year={2017}, month={Nov}, pages={4565–4584} }
 @misc{gopalswamy_uzsoy_2017, title={An iterative refinement approach to fitting clearing functions to data from simulation models of production systems}, url={http://dx.doi.org/10.1109/wsc.2017.8248043}, DOI={10.1109/wsc.2017.8248043}, abstractNote={We examine the problem of fitting clearing functions that estimate the expected output of a production resource as a function of its expected workload from empirical data. Unlike most regression problems, the independent variables are not directly controllable due to the presence of a planning model that controls releases to the production system, and the release decisions made by the planning model are themselves dependent on the estimated clearing function. We propose an iterative refinement procedure that uses simulation experiments to resample data from the production system as the parameters of the clearing function are iteratively updated. We compare the iterative procedure to previously used approaches with promising results.}, journal={2017 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Gopalswamy, Karthick and Uzsoy, Reha}, year={2017}, month={Dec} }
 @inproceedings{albey_yanikoglu_uzsoy_2017, title={Load dependent lead time modelling: A robust optimization approach}, booktitle={2017 winter simulation conference (wsc)}, author={Albey, E. and Yanikoglu, I. and Uzsoy, R.}, year={2017}, pages={3531–3542} }
 @article{orgut_ivy_uzsoy_2017, title={Modeling for the equitable and effective distribution of food donations under stochastic receiving capacities}, volume={49}, ISSN={["2472-5862"]}, DOI={10.1080/24725854.2017.1300358}, abstractNote={ABSTRACT We present and analyze stochastic models developed to facilitate the equitable and effective distribution of donated food by a regional food bank among the population at risk for hunger. Since demand typically exceeds the donated food supply, the food bank must distribute donated food in an equitable manner while minimizing food waste, leading to conflicting objectives. Distribution to beneficiaries in the service area is carried out by local charitable agencies, whose receiving capacities are stochastic, since they depend on factors (such as their budget and workforce) that vary significantly over time. We develop a single-period, two-stage stochastic model that ensures equitable distribution of food donations when the distribution decisions are made prior to observing capacities at the receiving locations. Shipment decisions made at the beginning of the period can be corrected at an additional cost after the capacities are observed in the second stage. We prove that this model has a newsvendor-type closed-form optimal solution and illustrate our results using historical data from our collaborating food bank.}, number={6}, journal={IISE TRANSACTIONS}, author={Orgut, Irem Sengul and Ivy, Julie and Uzsoy, Reha}, year={2017}, pages={567–578} }
 @article{albey_bilge_uzsoy_2017, title={Multi-dimensional clearing functions for aggregate capacity modelling in multi-stage production systems}, volume={55}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2016.1257169}, abstractNote={Nonlinear clearing functions have been proposed in the literature as metamodels to represent the behaviour of production resources that can be embedded in optimisation models for production planning. However, most clearing functions tested to date use a single-state variable to represent aggregate system workload over all products, which performs poorly when product mix affects system throughput. Clearing functions using multiple-state variables have shown promise, but require significant computational effort to fit the functions and to solve the resulting optimisation models. This paper examines the impact of aggregation in state variables on solution time and quality in multi-item multi-stage production systems with differing degrees of manufacturing flexibility. We propose multi-dimensional clearing functions using alternative aggregations of state variables, and evaluate their performance in computational experiments. We find that at low utilisation, aggregation of state variables has little effect on system performance; multi-dimensional clearing functions outperform single-dimensional ones in general; and increasing manufacturing flexibility allows the use of aggregate clearing functions with little loss of solution quality.}, number={14}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Albey, Erinc and Bilge, Umit and Uzsoy, Reha}, year={2017}, pages={4164–4179} }
 @inproceedings{uzsoy_2016, title={(Almost) present at the creation: 25 years of modelling and simulation in semiconductor manufacturing}, booktitle={2016 10th european conference on antennas and propagation (eucap)}, author={Uzsoy, R.}, year={2016}, pages={2509–2509} }
 @inproceedings{bansal_uzsoy_kempf k._2016, title={A Lagrangian Approach for Coordinating Capacity Negotiations in a Semiconductor Firm}, author={Bansal, A. and Uzsoy, R. and Kempf K., G}, year={2016}, month={Nov} }
 @inproceedings{albey_uzsoy_kempf_2016, title={A Lagrangian Relaxation Approach for a Multiproduct Stochastic Production Planning Problem}, author={Albey, E. and Uzsoy, R. and Kempf, K.G.}, year={2016}, month={Nov} }
 @inproceedings{wollmann_de sampaio_uzsoy_2016, title={A Systematic Literature Review of Rolling Methods for Production Planning}, author={Wollmann, R.G. and de Sampaio, R. and Uzsoy, R.}, year={2016}, month={Nov} }
 @inproceedings{albey_uzsoy_kempf_2016, title={A chance constraint based multi-item production planning model using simulation optimization}, booktitle={2016 winter simulation conference (wsc)}, author={Albey, E. and Uzsoy, R. and Kempf, K. G.}, year={2016}, pages={2719–2730} }
 @article{li_yang_uzsoy_xu_2016, title={A metamodel-based Monte Carlo simulation approach for responsive production planning of manufacturing systems}, volume={38}, ISSN={["1878-6642"]}, DOI={10.1016/j.jmsy.2015.11.004}, abstractNote={Production planning is concerned with finding a release plan of jobs into a manufacturing system so that its actual outputs over time match the customer demand with the least cost. For a given release plan, the system outputs, work in process inventory (WIP) levels and job completions, are non-stationary bivariate time series that interact with time series representing customer demand, resulting in the fulfillment/non-fulfillment of demand and the holding cost of both WIP and finished-goods inventory. The relationship between a release plan and its resulting performance metrics (typically, mean/variance of the total cost and the fill rate) has proven difficult to quantify. This work develops a metamodel-based Monte Carlo simulation (MCS) method to accurately capture the dynamic, stochastic behavior of a manufacturing system, and to allow real-time evaluation of a release plan's performance metrics. This evaluation capability is then embedded in a multi-objective optimization framework to search for near-optimal release plans. The proposed method has been applied to a scaled-down semiconductor fabrication system to demonstrate the quality of the metamodel-based MCS evaluation and the results of plan optimization.}, journal={JOURNAL OF MANUFACTURING SYSTEMS}, author={Li, Minqi and Yang, Feng and Uzsoy, Reha and Xu, Jie}, year={2016}, month={Jan}, pages={114–133} }
 @article{orgut_brock_davis_ivy_jiang_morgan_uzsoy_hale_middleton_2016, title={Achieving equity, effectiveness, and efficiency in food bank operations: Strategies for feeding America with implications for global hunger relief}, volume={235}, journal={Advances in managing humanitarian operations}, author={Orgut, I. S. and Brock, L. G. and Davis, L. B. and Ivy, J. S. and Jiang, S. and Morgan, S. D. and Uzsoy, R. and Hale, C. and Middleton, E.}, year={2016}, pages={229–256} }
 @article{lin_uzsoy_2016, title={Chance-constrained formulations in rolling horizon production planning: an experimental study}, volume={54}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2016.1165356}, abstractNote={Rolling horizon procedures, where an infinite horizon problem is approximated by the solution to a sequence of finite horizon problems, are common in production planning practice and research. However, these procedures also lead to frequent changes in planned release and production quantities, a phenomenon referred to as nervousness. We examine the performance of two chance-constrained production planning models developed for systems with stochastic demand in a rolling horizon environment, and find that these formulations significantly reduce planned release changes (nervousness) while also improving cost and service-level performance.}, number={13}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Lin, Po-Chen and Uzsoy, Reha}, year={2016}, pages={3927–3942} }
 @article{kesercioglu_roberts_uzsoy_2016, title={Computing the number of acute-care beds within NC Certificate of Need}, volume={5}, ISSN={["2047-6973"]}, DOI={10.1057/hs.2015.8}, abstractNote={North Carolina’s Certificate of Need legislation is intended to limit unnecessary growth in the number of acute-care beds throughout the state. In contrast to the current method of computing bed needs based on existing administrative units (counties), we estimate the service area of each acute-care facility using Voronoi diagrams such that the maximum distance from any point in the region to the nearest acute-care facility is minimized. The population in the service area is then used to determine the appropriate bed capacity for the hospital serving that region. The approach is applied to the problem of determining the appropriate number of acute-care beds for each hospital in the state. The discrepancies between the existing hospital sizes and the needed acute-care beds indicate areas where geographical inequities may need attention.}, number={2}, journal={HEALTH SYSTEMS}, author={Kesercioglu, Muge Gultekin and Roberts, Stephen D. and Uzsoy, Reha}, year={2016}, month={Jun}, pages={98–108} }
 @misc{uzsoy_2016, title={Demand Modeling with Forecast Evolution: An Application to Production Planning}, publisher={University of Wisconsin-Madison}, author={Uzsoy, R.}, year={2016}, month={Feb} }
 @inproceedings{kacar_uzsoy_2016, title={Estimating Clearing Functions for Production Resources using Simulation Optimization}, author={Kacar, N.B. and Uzsoy, R.}, year={2016}, month={Nov} }
 @inproceedings{gopalswamy_uzsoy_2016, title={Estimating Clearing Functions using Generalized Regression}, author={Gopalswamy, K. and Uzsoy, R.}, year={2016}, month={Nov} }
 @article{lin_uzsoy_2016, title={Estimating the costs of planned changes implied by freezing production plans}, volume={236}, journal={Heuristics, metaheuristics and approximate methods in planning and scheduling}, author={Lin, P. C. and Uzsoy, R.}, year={2016}, pages={17–44} }
 @misc{fowler_monch_uzsoy_2016, title={Modeling and Analysis of Semiconductor Supply Chains}, author={Fowler, J.W. and Monch, L. and Uzsoy, R.}, year={2016}, month={Feb} }
 @article{kacar_monch_uzsoy_2016, title={Modeling cycle times in production planning models for wafer fabrication}, volume={29}, DOI={10.1109/tsm.2016.2546314}, abstractNote={A key parameter of the linear programming (LP) models widely used for production planning in industry and academia are the lead times, the estimated delay between material becoming available to a resource and its completion at that resource. Lead times are commonly treated as exogenous, workload-independent parameters and assumed to be integer multiples of the planning period. Although formulations with non-integer lead times have been implemented in industry, we are unaware of any studies systematically evaluating their performance. In this paper, we compare the performance of LP models with and without non-integer lead times by simulating the execution of the resulting release plans. We also compare their performance to that of a formulation incorporating workload-dependent lead times using nonlinear clearing functions. We find that the performance of the models with non-integer lead times is substantially better than those with integer lead times, and often superior to that of the much more complex clearing function models. These results suggest that whenever reasonable estimates of the lead times are available, non-integer lead times should be used due to their simplicity of implementation and excellent performance.}, number={2}, journal={IEEE Transactions on Semiconductor Manufacturing}, author={Kacar, N. B. and Monch, L. and Uzsoy, Reha}, year={2016}, pages={153–167} }
 @article{orgut_ivy_uzsoy_wilson_2016, title={Modeling for the equitable and effective distribution of donated food under capacity constraints}, volume={48}, ISSN={["1545-8830"]}, DOI={10.1080/0740817x.2015.1063792}, abstractNote={Abstract Mathematical models are presented and analyzed to facilitate a food bank's equitable and effective distribution of donated food among a population at risk for hunger. Typically exceeding the donated supply, demand is proportional to the poverty population within the food bank's service area. The food bank seeks to ensure a perfectly equitable distribution of food; i.e., each county in the service area should receive a food allocation that is exactly proportional to the county's demand such that no county is at a disadvantage compared to any other county. This objective often conflicts with the goal of maximizing effectiveness by minimizing the amount of undistributed food. Deterministic network-flow models are developed to minimize the amount of undistributed food while maintaining a user-specified upper bound on the absolute deviation of each county from a perfectly equitable distribution. An extension of this model identifies optimal policies for the allocation of additional receiving capacity to counties in the service area. A numerical study using data from a large North Carolina food bank illustrates the uses of the models. A probabilistic sensitivity analysis reveals the effect on the models' optimal solutions arising from uncertainty in the receiving capacities of the counties in the service area.}, number={3}, journal={IIE TRANSACTIONS}, author={Orgut, Irem Sengul and Ivy, Julie and Uzsoy, Reha and Wilson, James R.}, year={2016}, pages={252–266} }
 @inproceedings{sengul orgut_ivy_uzsoy_2016, title={Modeling the Equitable and Effective Distribution of Food Donations under Stochastic Capacities}, author={Sengul Orgut, I. and Ivy, J.S. and Uzsoy, R.}, year={2016}, month={Nov} }
 @article{yaylali_ivy_uzsoy_samoff_meyer_maillard_2016, title={Modeling the effect of public health resources and alerting on the dynamics of pertussis spread}, volume={5}, ISSN={["2047-6973"]}, DOI={10.1057/hs.2015.6}, abstractNote={We consider the response of a local health department (LHD) to a pertussis outbreak using a composite discrete event simulation model with a stochastic branching process. The model captures the effect of epidemiologic spread of disease as a function of the health alert levels and the resource availability of the LHD. The primary response mode in the model is contact tracing that is assumed to be a resource-based delay with an iterative tracing policy. The effect of the threshold for initiating contact tracing and its relationship with the resource availability of the LHD is explored. The model parameters associated with contact tracing are estimated using North Carolina (NC), U.S.A. pertussis case data and data from the NC Public Health Information Network. The infectivity parameters are derived from literature. The results suggest that the time to initiate contact tracing significantly affects the magnitude and duration of the outbreak. The resource levels for contact tracing have less significant impact on the outbreak outcomes. However, when the nurse schedule is constrained, that is, if the total hours devoted to contact tracing a week is restricted, the effect of the resource level becomes significant. In fact, some outbreaks could not be controlled within the 1-year time limit of simulation.}, number={2}, journal={HEALTH SYSTEMS}, author={Yaylali, Emine and Ivy, Julie S. and Uzsoy, Reha and Samoff, Erika and Meyer, Anne Marie and Maillard, Jean Marie}, year={2016}, month={Jun}, pages={81–97} }
 @inproceedings{manda_uzsoy_kempf_kim_2016, title={Modeling the impact of new product introduction on the output of semiconductor wafer fabrication facilities}, booktitle={2016 winter simulation conference (wsc)}, author={Manda, A. B. and Uzsoy, R. and Kempf, K. G. and Kim, S.}, year={2016}, pages={2547–2558} }
 @inproceedings{manda_uzsoy_kempf_kim_2016, title={Modelling the Impact of New Product Introductions on Factory Throughput}, author={Manda, A.B. and Uzsoy, R. and Kempf, K.G. and Kim, S.}, year={2016}, month={Nov} }
 @inproceedings{arts_albey_uzsoy_de kok_orcun_2016, title={Solving Stochastic Inventory Problems by Integer Programming}, author={Arts, J. and Albey, E. and Uzsoy, R. and de Kok, A.G. and Orcun, S.}, year={2016}, month={Nov} }
 @article{fanti_ukovich_uzsoy_2016, title={Special section on emerging advances in logistics systems: Integrating remote sensing, IT, and autonomy}, volume={13}, number={4}, journal={IEEE Transactions on Automation Science and Engineering}, author={Fanti, M. P. and Ukovich, W. and Uzsoy, R.}, year={2016}, pages={1420–1421} }
 @inproceedings{kang_albey_uzsoy_2015, title={A Column Generation Approach for MultipleProduct Dynamic Lot Sizing with Congestion}, author={Kang, Y. and Albey, E. and Uzsoy, R.}, year={2015}, month={Aug} }
 @article{summerville_uzsoy_gaytán_2015, title={A random keys genetic algorithm for a bicriterion project selection and scheduling problem}, volume={2}, ISSN={2044-494X 2044-4958}, url={http://dx.doi.org/10.1504/ijps.2015.072105}, DOI={10.1504/ijps.2015.072105}, abstractNote={The project selection and scheduling problem involves the allocation of limited resources to competing projects over time to optimise a given objective function. However, in practical applications, multiple criteria need to be considered, leading us to formulate the problem as a multiple objective combinatorial optimisation (MOCO) model. Activities are subject to precedence constraints, as well as a budget limiting the capital available in each planning period. Interdependencies between projects by which the selection of specific subsets of projects may result in cost savings are also represented. We propose a genetic algorithm incorporating random keys and an efficient decoding procedure into the well-known NSGA-II procedure. The performance of this algorithm is evaluated in extensive computational experiments comparing the approximations of the Pareto-optimal set it obtains to those from NSGA-II.}, number={2}, journal={International Journal of Planning and Scheduling}, publisher={Inderscience Publishers}, author={Summerville, Natalia and Uzsoy, Reha and Gaytán, Juan}, year={2015}, pages={110} }
 @article{albey_norouzi_kempf_uzsoy_2015, title={Demand Modeling With Forecast Evolution: An Application to Production Planning}, volume={28}, ISSN={["1558-2345"]}, DOI={10.1109/tsm.2015.2453792}, abstractNote={The value of demand forecast information has been the subject of numerous studies in the inventory literature, but has had limited application in production planning. This paper integrates ideas from forecast evolution and inventory theory to plan work releases into a production facility in the face of stochastic demand. The model, which is solved on a rolling horizon basis, manages the inventory, backorder, and shortfall levels at each planning epoch using chance constraints to represent desired service levels. The evolution of demand information over time is modeled using the Martingale Model of Forecast Evolution. The model is implemented using historical data from a major semiconductor manufacturer. The value of forecast evolution is quantified using a benchmark model that does not consider forecast evolution.}, number={3}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Albey, Erinc and Norouzi, Amirhosein and Kempf, Karl G. and Uzsoy, Reha}, year={2015}, month={Aug}, pages={374–384} }
 @article{kacar_uzsoy_2015, title={Estimating Clearing Functions for Production Resources Using Simulation Optimization}, volume={12}, ISSN={["1558-3783"]}, DOI={10.1109/tase.2014.2303316}, abstractNote={We implement a gradient-based simulation optimization approach, the Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm, to estimate clearing functions (CFs) that describe the expected output of a production resource as a function of its expected workload from empirical data. Instead of trying to optimize the fit of the CF to the data, we seek values of the CF parameters that optimize the expected performance for the system when the fitted CFs are used to develop release schedules. A simulation model of a scaled-down wafer fabrication facility is used to generate the data and evaluate the performance of the CFs obtained from the SPSA. We show that SPSA significantly improves the production plan by either searching for better CF parameters or by directly optimizing releases.}, number={2}, journal={IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING}, author={Kacar, Necip Baris and Uzsoy, Reha}, year={2015}, month={Apr}, pages={539–552} }
 @article{kefeli_uzsoy_2015, title={Identifying potential bottlenecks in production systems using dual prices from a mathematical programming model}, volume={54}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207543.2015.1076182}, DOI={10.1080/00207543.2015.1076182}, abstractNote={The importance of identifying bottlenecks in production systems for effective production control and continuous improvement is well recognised. A useful definition of a bottleneck is the station to whose performance the performance of the overall production system is most sensitive. However, obtaining accurate estimates of the impact of changes in a given station's performance on the performance of a production system is often difficult. This paper uses the dual prices associated with production resources in a production planning model to support the identification of bottlenecks as the product mix in the system changes over time. The planning model considers queueing behaviour at production resources using non-linear clearing functions. Relationships between the dual prices of different resources are derived, and the bottleneck information obtained is compared to that from a model that does not consider queueing behaviour.}, number={7}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Kefeli, Ali and Uzsoy, Reha}, year={2015}, month={Sep}, pages={2000–2018} }
 @misc{albey_uzsoy_2015, title={Lead time modeling in production planning}, url={http://dx.doi.org/10.1109/wsc.2015.7408315}, DOI={10.1109/wsc.2015.7408315}, abstractNote={We use two mathematical models to represent the dependency between workload releases and lead times: a linear programming model with fractional lead times (FLT) and a clearing function (CF) based nonlinear model. In an attempt to obtain a reference solution, a gradient based simulation optimization procedure (SOP) is used to determine the lead times that, when used in the FLT model, yield the best performance. Results indicate that both FLT and CF models perform well, with CF approach performing slightly better at very high workload scenarios. The SOP is able to improve upon the performance of both models across all experimental conditions, suggesting that FLT and CF models are limited in representing the lead time dynamics. All three models yield quite different lead time patterns at critical machines, suggesting the need for further study of the behavior of these models.}, journal={2015 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Albey, Erinc and Uzsoy, Reha}, year={2015}, month={Dec} }
 @misc{ziarnetzky_kacar_monch_uzsoy_2015, title={Simulation-based performance assessment of production planning formulations for semiconductor wafer fabrication}, url={http://dx.doi.org/10.1109/wsc.2015.7408392}, DOI={10.1109/wsc.2015.7408392}, abstractNote={In this paper we compare two production planning formulations in a rolling horizon setting. The first is based on fixed lead times that are a multiple of the period length, while the second uses non-linear clearing functions. A scaled-down simulation model of a wafer fab is used to assess the performance of the two formulations. We examine the impact of the planning window and period length on the performance of the production planning formulations. The performance advantage of clearing functions that is observed in a static setting can be also observed in a rolling horizon setting.}, journal={2015 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Ziarnetzky, Timm and Kacar, N. Baris and Monch, Lars and Uzsoy, Reha}, year={2015}, month={Dec} }
 @article{aouam_uzsoy_2015, title={Zero-order production planning models with stochastic demand and workload-dependent lead times}, volume={53}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2014.935514}, abstractNote={We present three different formulations of a simple production planning problem that treat workload-dependent lead times, limited capacity and stochastic demand in an integrated fashion. We compare chance-constrained models, two-stage stochastic programming and robust optimisation using computational experiments. Our results show that the robust optimisation approach is promising, but all the different models face different but challenging issues in addressing this complex problem. We also conclude that successful approximations to this difficult problem with the potential for practical implementation can be developed.}, number={6}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Aouam, Tarik and Uzsoy, Reha}, year={2015}, month={Mar}, pages={1661–1679} }
 @misc{uzsoy_2014, title={(Almost) present at the creation: 25 years of modelling and simulation in semiconductor manufacturing}, url={http://dx.doi.org/10.1109/wsc.2014.7020094}, DOI={10.1109/wsc.2014.7020094}, abstractNote={Summary form only given. Over the last three decades an extensive research literature on modelling and simulation applications in the semiconductor industry has developed. Extensive relationships between academic research groups and industry have also been in evidence. This presentation will briefly review the evolution of modelling and analysis research in semiconductor manufacturing from an academic perspective, discuss its implications for academic research and industrial practice, and suggest a number of future directions for research and for more effective industry-university collaboration.}, journal={Proceedings of the Winter Simulation Conference 2014}, publisher={IEEE}, author={Uzsoy, Reha}, year={2014}, month={Dec} }
 @article{kacar_uzsoy_2014, title={A comparison of multiple linear regression approaches for fitting clearing functions to empirical data}, volume={52}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2013.864052}, abstractNote={We examine the problem of estimating clearing functions (CFs) that describe the expected output of a production resource as a function of its expected workload from empirical data. We use a simulation model of a scaled-down wafer fabrication facility to generate the data and evaluate the performance of the resulting CFs. We compare the performance of production plans generated using load based and product based CFs and find that using load based CFs yields better performance.}, number={11}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Kacar, Necip Baris and Uzsoy, Reha}, year={2014}, month={Jun}, pages={3164–3184} }
 @article{albey_bilge_uzsoy_2014, title={An exploratory study of disaggregated clearing functions for production systems with multiple products}, volume={52}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207543.2014.899442}, DOI={10.1080/00207543.2014.899442}, abstractNote={Clearing functions (CFs) have shown considerable promise for representing production capacity in production planning models due to their ability to capture the non-linear relationships between throughput, order releases and lead times. Most CFs developed to date use the total work in progress of all products, in units of processing time, as the state variable. In this paper, we investigate CFs for multi-product systems where the overall throughput of the system is affected by the product mix. We show that the aggregate work in process (WIP) variable used in the previous CF literature may lead to inaccurate estimates of expected throughput for individual products. To address this issue, we explore the use of multi-dimensional CFs (MDCFs) that use an extended definition of resource state based on the disaggregated WIP levels for individual products. Several new functional forms for MDCFs are postulated for single machine multi-product systems and their ability to represent system behaviour is assessed using simulation experiments. Results reveal that MDCFs are better able to predict system performance in the presence of mix-dependent capacity losses. We also discuss the extension of the MDCF approach to multi-stage production systems.}, number={18}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Albey, Erinç and Bilge, Ümit and Uzsoy, Reha}, year={2014}, month={Apr}, pages={5301–5322} }
 @inproceedings{lin_uzsoy_2014, title={Analysis of Release Changes with Fixed Lead Time and Capacity}, author={Lin, P.C. and Uzsoy, R.}, year={2014}, month={May} }
 @article{godinho filho_uzsoy_2014, title={Assessing the impact of alternative continuous improvement programmes in a flow shop using system dynamics}, volume={52}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2013.860249}, abstractNote={We use a system dynamics simulation model based on the Factory Physics perspective to study the cumulative effect of continuous improvement in arrival variability, process variability, defect rate, time to failure, repair time and set-up time on operating curves in a flow-shop environment. We find that small, simultaneous improvements at multiple locations in the line can provide reductions in cycle time comparable to, or sometimes superior to, those obtained by a major improvement at a single location. The reduction of process variability is often an excellent alternative to reducing the mean of a parameter, because process variability at a given station affects not only that station, but all downstream stations due to its impact on flow variability. Improvements at non-bottleneck stations also have significant benefits, again by reducing the variability of flow to the bottleneck station. These results suggest a broader interpretation of some aspects of the Theory of Constraints, and help explain the successful results of the Toyota Production System.}, number={10}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Godinho Filho, Moacir and Uzsoy, Reha}, year={2014}, month={May}, pages={3014–3031} }
 @book{pulat_sarin_uzsoy_2014, place={New York}, series={International Series in Operations Research & Management Science}, title={Essays in Production, Project Planning and Scheduling}, ISBN={9781461490555 9781461490562}, ISSN={0884-8289 2214-7934}, url={http://dx.doi.org/10.1007/978-1-4614-9056-2}, DOI={10.1007/978-1-4614-9056-2}, abstractNote={From the Preface: This festschrift is devoted to recognize the career of a man who not only witnessed the growth of operations research from its inception, but also contributed significantly to this g}, publisher={Springer US}, year={2014}, collection={International Series in Operations Research & Management Science} }
 @article{norouzi_uzsoy_2014, title={Modeling the evolution of dependency between demands, with application to inventory planning}, volume={46}, ISSN={["1545-8830"]}, DOI={10.1080/0740817x.2013.803637}, abstractNote={This article shows that the progressive realization of uncertain demands across successive discrete time periods through additive or multiplicative forecast updates results in the evolution of the conditional covariance of demand in addition to its conditional mean. A dynamic inventory model with forecast updates is used to illustrate the application of the proposed method. It is shown that the optimal inventory policy depends on conditional covariances, and a model without information updates is used to quantify the benefit of using the available forecast information in the presence of additive forecast updates. The proposed approach yields significant reductions in system costs and is applicable to a wide range of production and inventory models. It is also shown that the proposed approach can be extended to the case of multiplicative forecast updates and directions for future work are suggested.}, number={1}, journal={IIE TRANSACTIONS}, author={Norouzi, Amirhosein and Uzsoy, Reha}, year={2014}, month={Jan}, pages={55–66} }
 @article{giddings_rardin_uzsoy_2014, title={Statistical optimum estimation techniques for combinatorial optimization problems: a review and critique}, volume={20}, ISSN={["1572-9397"]}, DOI={10.1007/s10732-014-9243-4}, number={3}, journal={JOURNAL OF HEURISTICS}, author={Giddings, Angela P. and Rardin, Ronald L. and Uzsoy, Reha}, year={2014}, month={Jun}, pages={329–358} }
 @article{kang_albey_hwang_uzsoy_2014, title={The impact of lot-sizing in multiple product environments with congestion}, volume={33}, ISSN={["1878-6642"]}, DOI={10.1016/j.jmsy.2014.04.003}, abstractNote={We present a production planning model for a multiple product single machine dynamic lot-sizing problem with congestion. Using queuing models, we develop a set of functions to capture the nonlinear relationship between the output, lot sizes and available work in process inventory levels of all products in the system. We then embed these functions in a nonlinear optimization model with continuous variables, and construct an approximate solution to the original problem by rounding the resulting fractional solution. Computational experiments show that our model with congestion provides significantly better flow time and inventory performance than a benchmark model that does not consider the effects of congestion. These advantages arise from the use of multiple smaller lots in a period instead of a single large lot as suggested by conventional fixed-charge models without congestion.}, number={3}, journal={JOURNAL OF MANUFACTURING SYSTEMS}, author={Kang, Yongha and Albey, Erinc and Hwang, Sangwook and Uzsoy, Reha}, year={2014}, month={Jul}, pages={436–444} }
 @misc{kacar_monch_uzsoy_2013, title={A comparison of production planning formulations with exogenous cycle time estimates using a large-scale wafer fab model}, url={http://dx.doi.org/10.1109/wsc.2013.6721733}, DOI={10.1109/wsc.2013.6721733}, abstractNote={A key parameter of the linear programming (LP) models widely used for production planning in industry and academia are the lead times, the estimated delay between material becoming available to a resource and the completion of its processing at that resource. Lead times are commonly treated as exogenous, workload-independent parameters and assumed to be integer multiples of the planning period. Although formulations with non-integer lead times have been proposed in the past, we are not aware of any studies that systematically evaluate the benefits of using non-integer lead times in LP models. In this paper we implement LP models to plan the releases of wafers into a large-scale wafer fabrication facility and compare the performance of LP models with and without non-integer lead times by simulating the execution of the resulting release plans. We find that the models with non-integer lead times yield substantially improved performance, and are quite straightforward to implement.}, journal={2013 Winter Simulations Conference (WSC)}, publisher={IEEE}, author={Kacar, N. Baris and Monch, Lars and Uzsoy, Reha}, year={2013}, month={Dec} }
 @inproceedings{albey_uzsoy_2013, title={Improving Shop Floor Level Performance in a Dynamic Lot Sizing Environment with Congestion}, author={Albey, E. and Uzsoy, R.}, year={2013}, month={May} }
 @misc{upasani_uzsoy_2013, title={Integrated Production Planning and Pricing Decisions in Congestion-Prone Capacitated Production Systems}, ISBN={9781461490555 9781461490562}, ISSN={0884-8289 2214-7934}, url={http://dx.doi.org/10.1007/978-1-4614-9056-2_3}, DOI={10.1007/978-1-4614-9056-2_3}, abstractNote={In many industries both the pricing of a product and its delivery lead time to the customer are significant factors affecting demand. However, it is well known from queuing models that the lead time increases nonlinearly with the utilization of capacitated resources. Hence when customer demand is sensitive to delivery lead times, firms must take a broader view: A large reduction in price may increase demand to the point that it cannot be met in a timely manner with available capacity, which can adversely affect customer satisfaction and reduce future sales. In this chapter we develop an integrated model for dynamic pricing and production planning for a single product under workload-dependent lead times. This allows us to capture interactions between pricing, sales and lead times that have generally not been considered in the past. We present numerical examples to demonstrate these interactions, as well as analytical results showing that the proposed model behaves quite differently from conventional models that ignore congestion.}, journal={International Series in Operations Research & Management Science}, publisher={Springer US}, author={Upasani, Abhijit and Uzsoy, Reha}, year={2013}, month={Dec}, pages={29–68} }
 @article{hosking_roberts_uzsoy_joseph_2013, title={Investigating interventions for increasing colorectal cancer screening: Insights from a simulation model}, volume={47}, ISSN={0038-0121}, url={http://dx.doi.org/10.1016/j.seps.2012.10.001}, DOI={10.1016/j.seps.2012.10.001}, abstractNote={We develop a discrete-event-continuous simulation model of colorectal cancer screening in North Carolina to examine the impact of six different interventions on the fraction of eligible patients receiving the clinically recommended screening. We find that demand side interventions alone are less effective than using only supply side interventions or a combination of both; the single most effective intervention is implementing a patient reminder system to reduce the number of no-show patients; and that all interventions studied are subject to significant diminishing returns.}, number={2}, journal={Socio-Economic Planning Sciences}, publisher={Elsevier BV}, author={Hosking, Michael and Roberts, Stephen and Uzsoy, Reha and Joseph, Talisa M.}, year={2013}, month={Jun}, pages={142–155} }
 @inproceedings{lin_uzsoy_2013, title={Minimizing End Effects in Rolling Horizon Algorithms for Production Planning: An Experimental Study}, author={Lin, P.C. and Uzsoy, R.}, year={2013}, month={May} }
 @article{kim_uzsoy_2013, title={Modeling and Analysis of Integrated Planning of Production and Engineering Process Improvement}, volume={26}, ISSN={0894-6507 1558-2345}, url={http://dx.doi.org/10.1109/tsm.2013.2261099}, DOI={10.1109/tsm.2013.2261099}, abstractNote={A clearing function that can capture the nonlinear relationship between workloads and throughput and also reflect capacity improvement by engineering activities on a multioperation workcenter is developed. The clearing function is then used to formulate an integrated optimization model for planning both production and engineering process improvement. Marginal cost analysis using the Karush-Kuhn-Tucker optimality conditions provides useful insights into effective management of resources in a reentrant manufacturing system.}, number={3}, journal={IEEE Transactions on Semiconductor Manufacturing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Kim, Sukgon and Uzsoy, Reha}, year={2013}, month={Aug}, pages={414–422} }
 @inproceedings{sengul_ivy_uzsoy_2013, title={Modeling for Equitable Food Distribution in North Carolina}, author={Sengul, I. and Ivy, J.S. and Uzsoy, R.}, year={2013}, month={May} }
 @article{kacar_moench_uzsoy_2013, title={Planning Wafer Starts using Nonlinear Clearing Functions: A Large-Scale Experiment}, volume={26}, ISSN={["1558-2345"]}, DOI={10.1109/tsm.2013.2283038}, abstractNote={The nonlinear, circular dependency between workload and cycle times for production resources governed by queueing behavior has been a longstanding difficulty in the production planning domain. The issue is particularly important for semiconductor wafer fabrication facilities, which must operate at relatively high utilization to be profitable. Nonlinear clearing functions that relate the expected output of a resource in a planning period to the amount of work available to it have been proposed as an alternative approach. While computational tests on small systems have been promising, the question of whether the results remain valid for large-scale systems has remained open. In this paper we evaluate the performance of a clearing function based production planning model using a simulation of a large-scale wafer fab with two products and several hundred operations. Results indicate that, consistent with the results of previous experiments, the clearing function model yields substantial improvements in profit over conventional linear programming models.}, number={4}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Kacar, Necip Baris and Moench, Lars and Uzsoy, Reha}, year={2013}, month={Nov}, pages={602–612} }
 @inproceedings{kacar_moench_uzsoy_2013, title={Production Planning using Nonlinear Clearing Functions: A Review of Recent Results}, author={Kacar, N.B. and Moench, L. and Uzsoy, R.}, year={2013}, month={Feb} }
 @inproceedings{norouzi_uzsoy_2013, title={Production Planning with Load-Dependent Lead Times and Uncertain Demands}, author={Norouzi, A. and Uzsoy, R.}, year={2013}, month={May} }
 @article{godinho filho_uzsoy_2013, title={The impact of simultaneous continuous improvement in setup time and repair time on manufacturing cycle times under uncertain conditions}, volume={51}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2011.652261}, abstractNote={We develop a system dynamics model to examine the cumulative effects of continuous improvement programmes for repair and setup times on the cycle time of a simple single-stage production system. The relationship between system performance and repair and setup times is captured using the Factory Physics approach. We find that modest rates of improvement in multiple areas in parallel yield cumulative benefits over time comparable with those obtained by a large reduction in a single parameter, especially when there is significant uncertainty in the degree of improvement that can be obtained, or in the degree to which improvements can be sustained over time. These results provide an insight into the success of the Toyota Production System and related lean manufacturing approaches where continuous improvement is an ongoing activity across the work environment.}, number={2}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Godinho Filho, Moacir and Uzsoy, Reha}, year={2013}, pages={447–464} }
 @inproceedings{kacar_monch_uzsoy_2013, title={Using Clearing Functions for Production Planning in Large-Scale Wafer Fabs}, author={Kacar, N.B. and Monch, L. and Uzsoy, R.}, year={2013}, month={May} }
 @article{kacar_irdem_uzsoy_2012, title={An Experimental Comparison of Production Planning Using Clearing Functions and Iterative Linear Programming-Simulation Algorithms}, volume={25}, ISSN={["0894-6507"]}, DOI={10.1109/tsm.2011.2176560}, abstractNote={We compare the performance of three algorithms for production planning with workload-dependent lead times. These include a clearing function model using two different methods for estimating the clearing functions, and two iterative algorithms that combine linear programming and simulation models. Our experimental comparison uses a simulation model of a re-entrant bottleneck system built with attributes of a real-world semiconductor fabrication environment. We vary the bottleneck utilization, demand patterns, the mean time to failure, and the mean time to repair. Results indicate that the clearing function model performs better than the iterative algorithms on the scaled-down system considered, giving less variable production plans and higher profit values.}, number={1}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Kacar, Necip Baris and Irdem, Durmus Fatih and Uzsoy, Reha}, year={2012}, month={Jan}, pages={104–117} }
 @misc{aouam_uzsoy_2012, title={Chance-Constraint-Based Heuristics for Production Planning in the Face of Stochastic Demand and Workload-Dependent Lead Times}, ISBN={9780857296436 9780857296443}, url={http://dx.doi.org/10.1007/978-0-85729-644-3_8}, DOI={10.1007/978-0-85729-644-3_8}, journal={Decision Policies for Production Networks}, publisher={Springer London}, author={Aouam, Tarik and Uzsoy, Reha}, year={2012}, pages={173–208} }
 @inproceedings{kim_uzsoy_2012, title={Engineering Process Improvement for Wafer Fabrication}, author={Kim, S. and Uzsoy, R.}, year={2012}, month={May} }
 @inproceedings{ivy_sengul_uzsoy_2012, title={Modeling for Equitable Food Distribution Under Capacity Constraints}, author={Ivy, J.S. and Sengul, I. and Uzsoy, R.}, year={2012}, month={May} }
 @article{armbruster_uzsoy_2012, title={Multiple Time Scales in Production Planning: Clearing Functions, Discrete-Event Simulation and Partial Differential Equations}, journal={Tutorials in Operations Research}, author={Armbruster, D. and Uzsoy, R.}, year={2012} }
 @inproceedings{albey_bilge_uzsoy_2012, title={Performance of an Iterative Production Planning Approach for Production Systems with Manufacturing Flexibility}, author={Albey, E. and Bilge, U. and Uzsoy, R.}, year={2012}, month={Feb} }
 @inproceedings{viktorovna_gaytan iniestra_uzsoy_2011, title={A New Genetic Algorithm for Multicriteria Project Selection and Scheduling}, author={Viktorovna, N. and Gaytan Iniestra, J. and Uzsoy, R.}, year={2011}, month={Nov} }
 @inproceedings{jarugumilli_uzsoy_2011, title={A Nonlinear Knapsack Problem Arising in Location Problems with Safety Stocks}, author={Jarugumilli, K. and Uzsoy, R.}, year={2011}, month={Nov} }
 @inproceedings{albey_bilge_uzsoy_2011, title={Estimating Clearing Functions for Multistage Production Systems with Alternative Machines}, author={Albey, E. and Bilge, U. and Uzsoy, R.}, year={2011}, month={Nov} }
 @inproceedings{kacar_uzsoy_2011, title={Estimating Clearing Functions from Simulation Data}, author={Kacar, N.B. and Uzsoy, R.}, year={2011}, month={Nov} }
 @inproceedings{carr_gultekin_roberts_uzsoy_2011, title={Geography in Healthcare Planning}, author={Carr, S. and Gultekin, M. and Roberts, S. and Uzsoy, R.}, year={2011}, month={May} }
 @misc{kang_albey_hwang_uzsoy_2011, title={Heuristics for Multiproduct Dynamic Lot Sizing with Congestion}, author={Kang, Y. and Albey, E. and Hwang, S. and Uzsoy, R.}, year={2011}, month={Jul} }
 @inproceedings{norouzi_uzsoy_2011, title={Modeling the Conditional Covariance of Demands with Application to Production Planning}, author={Norouzi, A. and Uzsoy, R.}, year={2011}, month={Nov} }
 @inproceedings{yaylali_ivy_uzsoy_2011, title={Modeling the Effect of Public Health Resources and Alerting on the Dynamics of Pertussis Spread}, author={Yaylali, E. and Ivy, J.S. and Uzsoy, R.}, year={2011}, month={Nov} }
 @article{chien_dauzere-peres_ehm_fowler_jiang_krishnaswamy_lee_monch_uzsoy_2011, title={Modelling and analysis of semiconductor manufacturing in a shrinking world: Challenges and successes}, volume={5}, number={3}, journal={European Journal of Industrial Engineering}, author={Chien, C. F. and Dauzere-Peres, S. and Ehm, H. and Fowler, J. W. and Jiang, Z. B. and Krishnaswamy, S. and Lee, T. E. and Monch, L. and Uzsoy, R.}, year={2011}, pages={254–271} }
 @inproceedings{yaylali_uzsoy_worth_maillard_meyer_samoff_wendelboe_2011, title={Modelling the Effect of Public Health Resources on the Dynamic of Pertussis Outbreaks}, author={Yaylali, E. and Uzsoy, R. and Worth, T. and Maillard, J.M. and Meyer, A.M. and Samoff, E. and Wendelboe, A.}, year={2011}, month={Jun} }
 @book{kempf_keskinocak_uzsoy_2011, place={New York}, title={Planning in the Extended Enterprise: A State of the Art Handbook}, volume={2}, publisher={Springer}, year={2011} }
 @article{crist_uzsoy_2011, title={Prioritising production and engineering lots in wafer fabrication facilities: a simulation study}, volume={49}, ISSN={["1366-588X"]}, DOI={10.1080/00207541003801259}, abstractNote={Due to the high cost of equipment, most semiconductor wafer fabrication facilities process both regular production lots which are shipped to customers and engineering lots that support product and process development efforts. The different objectives of the engineering and production organisations render the problem of allocating equipment capacity between these different types of lots a difficult and often contentious problem. In this paper we explore the impacts of several different policies for allocating resources to production and engineering work on the shop floor using a scaled-down simulation model of a wafer fabrication facility. Our results indicate that the availability and flexibility of engineering resources can affect the performance of scheduling policies in quite different ways. We conclude that this problem needs to be viewed in a broader context than that of a shop floor scheduling issue, including the level of available engineering resources, their degree of cross-training and the manner in which engineers are allocated to different projects.}, number={11}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Crist, Kristy and Uzsoy, Reha}, year={2011}, pages={3105–3125} }
 @misc{uzsoy_2011, title={Production Planning with Resources Subject to Congestion}, author={Uzsoy, R.}, year={2011}, month={Sep} }
 @misc{uzsoy_2011, title={Production Planning with Resources Subject to Congestion}, author={Uzsoy, R.}, year={2011}, month={Mar} }
 @misc{uzsoy_2011, title={Production Planning with Workload-Dependent Lead Times and Uncertain Demand}, author={Uzsoy, R.}, year={2011}, month={Dec} }
 @misc{liu_li_yang_wan_uzsoy_2011, title={Production planning for semiconductor manufacturing via simulation optimization}, url={http://dx.doi.org/10.1109/wsc.2011.6148055}, DOI={10.1109/wsc.2011.6148055}, abstractNote={This paper is concerned with production planning in manufacturing, which can be loosely defined as the problem of finding a release plan for jobs that minimizes the total cost (or maximizes the total profit). Production planning is a challenging optimization problem due to the variability in manufacturing systems and uncertainty in future demand, both of which have not been adequately addressed by existing production planning models. To address both these issues, this paper formulates the production planning problem as a simulation-based multi-objective optimization problem, and adapts a genetic algorithm to search for a set of release plans that are near-Pareto optimal. The solutions from the simulation optimization approach can serve as a useful benchmark for existing and new production planning methods.}, journal={Proceedings of the 2011 Winter Simulation Conference (WSC)}, publisher={IEEE}, author={Liu, Jingang and Li, Chihui and Yang, Feng and Wan, Hong and Uzsoy, Reha}, year={2011}, month={Dec} }
 @article{ravindran_kempf_uzsoy_2011, title={Production planning with load-dependent lead times and safety stocks for a single product}, volume={1}, ISSN={2044-494X 2044-4958}, url={http://dx.doi.org/10.1504/ijps.2011.044547}, DOI={10.1504/ijps.2011.044547}, abstractNote={Queuing models have demonstrated the nonlinear relationship between resource utilisation, which is determined by production planning decisions, and lead times. Both production planning decisions and safety stock levels are driven by lead times, and are thus tightly interrelated. However, production planning and safety stock calculations have generally been carried out separately. We propose a production planning model for a single–stage single–product system that integrates release planning and safety stock considerations. Concave clearing functions are used to capture the nonlinear relationship between resource utilisation and lead times, while chance constraints represent the need to plan inventories to achieve desired service levels. Extensive computational experiments indicate that the proposed model provides an excellent tradeoff between customer service and inventory costs.}, number={1/2}, journal={International Journal of Planning and Scheduling}, publisher={Inderscience Publishers}, author={Ravindran, Ashwin and Kempf, Karl G. and Uzsoy, Reha}, year={2011}, pages={58} }
 @misc{orcun_uzsoy_2011, title={The Effects of Production Planning on the Dynamic Behavior of a Simple Supply Chain: An Experimental Study}, ISBN={9781441981905 9781441981912}, ISSN={0884-8289}, url={http://dx.doi.org/10.1007/978-1-4419-8191-2_3}, DOI={10.1007/978-1-4419-8191-2_3}, abstractNote={Sophisticated supply chain planning systems, also known as Advanced Planning and Scheduling (APS) systems, have become commonplace in industry, and constitute a multibillion dollar software industry (Musselman and Uzsoy 2001; de Kok and Fransoo 2003; Stadtler and Kilger 2004). Many of these models rely to some degree on mathematical programming formulations of multistage productioninventory systems, which have been discussed extensively by (Saad 1982; Voss and Woodruff 2003; Johnson andMontgomery 1974; Hax and Candea 1984) and in this volume by Missbauer and Uzsoy. However, there has been little study in the literature of the effects of these production planning models on the dynamic behavior of supply chains. The dynamic behavior of supply chains over time has been studied in the system dynamics literature for several decades (Sterman 2000; Forrester 1962), leading to a growing understanding of the effects of information and material delays on the behavior of these systems, such as the bullwhip effect (Chen et al. 1998; Chen et al. 2000; Dejonckheere et al. 2003; Dejonckheere et al. 2004). However, the production planning procedures used in these models are generally feedback control procedures, with little ability to predict future states of the system and behave in a reactive manner. It is also quite difficult to interface optimization-based production planning models to standard system dynamics software. Hence, there is very little work of which we are aware that examines the effect of optimization-based planning procedures on the dynamic behavior of the supply chain in a systematic manner.}, journal={International Series in Operations Research & Management Science}, publisher={Springer New York}, author={Orcun, Seza and Uzsoy, Reha}, year={2011}, pages={43–80} }
 @article{godinho filho_uzsoy_2011, title={The effect of shop floor continuous improvement programs on the lot size-cycle time relationship in a multi-product single-machine environment}, volume={52}, ISSN={["1433-3015"]}, DOI={10.1007/s00170-010-2770-8}, number={5-8}, journal={INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY}, author={Godinho Filho, Moacir and Uzsoy, Reha}, year={2011}, month={Feb}, pages={669–681} }
 @article{kefeli_uzsoy_fathi_kay_2011, title={Using a mathematical programming model to examine the marginal price of capacitated resources}, volume={131}, ISSN={["1873-7579"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79952613605&partnerID=MN8TOARS}, DOI={10.1016/j.ijpe.2010.03.018}, abstractNote={Accurate information on dual prices of capacitated resources is of interest in a number of applications, such as cost allocation and pricing. To gain insight we focus on the dual prices of capacity and demand in a single-stage single-product production-inventory system, and discuss their interpretation. In particular, we examine the behavior of two different production planning models: a conventional linear programming model and a nonlinear model that captures queuing behavior at resources in an aggregate manner using nonlinear clearing functions. The classical linear programming formulation consistently underestimates the dual price of capacity due to its failure to capture the effects of queuing. The clearing function formulation, in contrast, produces positive dual prices even when utilization is below one and exhibits more realistic behavior, such as holding finished inventory at utilization levels below one.}, number={1}, journal={INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS}, author={Kefeli, Ali and Uzsoy, Reha and Fathi, Yahya and Kay, Michael}, year={2011}, month={May}, pages={383–391} }
 @inproceedings{kang_uzsoy_2010, title={A Column Generation Approach for Multiple Product Dynamic Lot Sizing with Congestion}, author={Kang, Y. and Uzsoy, R.}, year={2010}, month={Jun} }
 @inproceedings{kefeli_uzsoy_2010, title={A Dantzig-Wolfe Decomposition Approach to Dual-Rich Production Planning Models}, author={Kefeli, A. and Uzsoy, R.}, year={2010}, month={Jun} }
 @article{irdem_kacar_uzsoy_2010, title={An Exploratory Analysis of Two Iterative Linear Programming-Simulation Approaches for Production Planning}, volume={23}, ISSN={["1558-2345"]}, DOI={10.1109/tsm.2010.2051751}, abstractNote={Production planning models that aim at determining optimal release schedules for production facilities face a fundamental circularity. In order to match supply to demand in an optimal manner, they must recognize the cycle time that elapses between material being released into the plant and its emergence as finished product. However, it is well known from queuing models that the mean cycle time increases nonlinearly with resource utilization, which is determined by the release schedule. To address this circularity, a number of authors have suggested algorithms which iterate between a linear programming model that determines releases for a set of flow time estimates, and a simulation model that evaluates the production realized from that release schedule. We present computational experiments examining the behavior of two such algorithms. We find that the convergence behavior of one is significantly more consistent than that of the other, and explore insights that may lead to improved algorithms.}, number={3}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Irdem, D. Fatih and Kacar, N. Baris and Uzsoy, Reha}, year={2010}, month={Aug}, pages={442–455} }
 @inproceedings{kacar_uzsoy_2010, title={Comparing Production Planning with Clearing Functions and Iterative Simulation-LP Algorithms}, author={Kacar, N.B. and Uzsoy, R.}, year={2010}, month={Jun} }
 @inproceedings{kacar_uzsoy_2010, title={Estimating clearing functions from simulation data}, booktitle={Proceedings of the 2010 winter simulation conference}, author={Kacar, N. B. and Uzsoy, R.}, year={2010}, pages={1699–1710} }
 @inproceedings{jarugumilli_uzsoy_2010, title={Generating Problem Instances with Known Optima for Facility Location Problems: A Cautionary Tale}, author={Jarugumilli, K. and Uzsoy, R.}, year={2010}, month={Jun} }
 @misc{worth_uzsoy_samoff_meyer_maillard_wendelboe_2010, title={Modelling the response of a public health department to infectious disease}, url={http://dx.doi.org/10.1109/wsc.2010.5678917}, DOI={10.1109/wsc.2010.5678917}, abstractNote={We present a discrete-event simulation model of the response of a local public health department (LHD) to pertussis cases. We take a comprehensive view of public health actions, beginning with detection of an individual patient, confirmation of the case by physician and lab tests, and contact tracing and isolation of contacts by LHD personnel. We explicitly model the information transfer between providers, laboratories and LHDs, and examine the effect of different alerting strategies on the number of confirmed cases encountered. The effect of limited resource availability for contact tracing is also examined. Given our results, we suggest that resource availability has significant impact on the progression of a disease outbreak, as do information delays at various stages of the process.}, journal={Proceedings of the 2010 Winter Simulation Conference}, publisher={IEEE}, author={Worth, Travis and Uzsoy, Reha and Samoff, Erika and Meyer, Anne-Marie and Maillard, Jean-Marie and Wendelboe, Aaron M.}, year={2010}, month={Dec} }
 @inproceedings{gaytan_uzsoy_viktorovna_2010, title={Multiobjective Combinatorial Optimization Model for Project Scheduling in the Tourism Sector}, author={Gaytan, J. and Uzsoy, R. and Viktorovna, N.}, year={2010}, month={Jun} }
 @inbook{missbauer_uzsoy_2010, place={New York}, series={International Series in Operations Research & Management Science}, title={Optimization Models of Production Planning Problems}, ISBN={9781441964847 9781441964854}, ISSN={0884-8289 2214-7934}, url={http://dx.doi.org/10.1007/978-1-4419-6485-4_16}, DOI={10.1007/978-1-4419-6485-4_16}, booktitle={Planning Production and Inventories in the Extended Enterprise}, publisher={Springer US}, author={Missbauer, Hubert and Uzsoy, Reha}, editor={Kempf, K.G. and Keskinocak, P. and Uzsoy, R.Editors}, year={2010}, month={Oct}, pages={437–507}, collection={International Series in Operations Research & Management Science} }
 @book{kempf_keskinocak_uzsoy_2010, place={New York}, title={Planning in the Extended Enterprise: A State of the Art Handbook}, volume={1}, publisher={Springer}, year={2010} }
 @inproceedings{norouzi_uzsoy_2010, title={Planning of Work Releases and Safety Stocks with Forecast Evolution}, author={Norouzi, A. and Uzsoy, R.}, year={2010}, month={Jun} }
 @inproceedings{uzsoy_2010, title={Production Planning with Resources Subject to Congestion}, author={Uzsoy, R.}, year={2010}, month={Jul} }
 @inproceedings{uzsoy_2010, title={Production Planning with Resources Subject to Congestion}, author={Uzsoy, R.}, year={2010}, month={Jun} }
 @misc{uzsoy_2010, title={Production Planning with Resources Subject to Congestion}, author={Uzsoy, R.}, year={2010}, month={Mar} }
 @misc{uzsoy_2010, title={Production Planning with Resources Subject to Congestion}, author={Uzsoy, R.}, year={2010}, month={Sep} }
 @article{sourirajan_ozsen_uzsoy_2009, title={A genetic algorithm for a single product network design model with lead time and safety stock considerations}, volume={197}, ISSN={["1872-6860"]}, DOI={10.1016/j.ejor.2008.07.038}, abstractNote={We consider a two-stage supply chain with a production facility that replenishes a single product at retailers. The objective is to locate distribution centers in the network such that the sum of facility location, pipeline inventory, and safety stock costs is minimized. We explicitly model the relationship between the flows in the network, lead times, and safety stock levels. We use genetic algorithms to solve the model and compare their performance to that of a Lagrangian heuristic developed in earlier work. A novel chromosome representation that combines binary vectors with random keys provides solutions of similar quality to those from the Lagrangian heuristic. The model is then extended to incorporate arbitrary demand variance at the retailers. This modification destroys the structure upon which the Lagrangian heuristic is based, but is easily incorporated into the genetic algorithm. The genetic algorithm yields significantly better solutions than a greedy heuristic for this modification and has reasonable computational requirements.}, number={2}, journal={EUROPEAN JOURNAL OF OPERATIONAL RESEARCH}, author={Sourirajan, Karthik and Ozsen, Leyla and Uzsoy, Reha}, year={2009}, month={Sep}, pages={599–608} }
 @article{orcun_uzsoy_kempf_2009, title={An integrated production planning model with load-dependent lead-times and safety stocks}, volume={33}, ISSN={["0098-1354"]}, DOI={10.1016/j.compchemeng.2009.07.010}, abstractNote={The divergence over the years of research paradigms addressing the production planning problem has led to the development of an extensive set of techniques, each of which can address a particular aspect of the practical problem and none of which provides a complete solution. In particular, most approaches fail to address the circular, non-linear dependency between resource utilization, lead-times and safety stocks. We present a non-linear programming formulation of the integrated problem using clearing functions that determines a work release schedule guaranteeing a specified service level in the face of stochastic demand. We introduce an iterative heuristic solution procedure that solves a relaxed LP approximation of the original NLP at each iteration to determine the lead-time profile to set safety-stock levels. Computational experiments suggest that our proposed iterative procedure performs well relative to conventional LP models that assume fixed, workload-independent lead-times.}, number={12}, journal={COMPUTERS & CHEMICAL ENGINEERING}, author={Orcun, Seza and Uzsoy, Reha and Kempf, Karl G.}, year={2009}, month={Dec}, pages={2159–2163} }
 @inproceedings{irdem_kacar_uzsoy_2009, title={Comparison of Iterative Simulation-Optimization Algorithms for Production Planning of a Semiconductor Manufacturing Line}, author={Irdem, D.F. and Kacar, N.B. and Uzsoy, R.}, year={2009}, month={Jan} }
 @inproceedings{kefeli_uzsoy_fathi_kay_2009, title={Dual Prices in Multi-Product Production Planning Models with Congested Resources}, author={Kefeli, A. and Uzsoy, R. and Fathi, Y. and Kay, M.}, year={2009}, month={Jan} }
 @article{kim_uzsoy_2009, title={Heuristics for capacity planning problems with congestion}, volume={36}, ISSN={0305-0548}, url={http://dx.doi.org/10.1016/j.cor.2008.06.006}, DOI={10.1016/j.cor.2008.06.006}, abstractNote={Motivated by a problem in the semiconductor industry, we develop improved formulations for the problem of planning capacity acquisition and deletion over time when resources are subject to congestion, motivated by a problem in the semiconductor industry. We use nonlinear clearing functions to relate the expected output of a production resource in a planning period to the expected work in process (WIP) inventory level. Exploiting the properties of the clearing function allows us to formulate the single workcenter problem as a shortest path problem. This forms the basis for two greedy constructive heuristics and a Lagrangian heuristic for the multistage problem. The latter procedure also provides lower bounds on the optimal value. We present computational experiments showing that the proposed heuristics obtain high-quality solutions in modest CPU times.}, number={6}, journal={Computers & Operations Research}, publisher={Elsevier BV}, author={Kim, Sukgon and Uzsoy, Reha}, year={2009}, month={Jun}, pages={1924–1934} }
 @misc{uzsoy_2009, title={Production Planning with Resources Subject to Congestion}, author={Uzsoy, R.}, year={2009}, month={Feb} }
 @article{asmundsson_rardin_turkseven_uzsoy_2009, title={Production planning with resources subject to congestion}, volume={56}, ISSN={0894-069X 1520-6750}, url={http://dx.doi.org/10.1002/nav.20335}, DOI={10.1002/nav.20335}, abstractNote={Abstract}, number={2}, journal={Naval Research Logistics}, publisher={Wiley}, author={Asmundsson, Jakob and Rardin, Ronald L. and Turkseven, Can Hulusi and Uzsoy, Reha}, year={2009}, month={Mar}, pages={142–157} }
 @inproceedings{irdem_kacar_uzsoy_2008, title={An Experimental study of an iterative simulation-optimization algorithm for production planning}, booktitle={2008 Winter Simulation Conference, vols 1-5}, author={Irdem, D. F. and Kacar, N. B. and Uzsoy, R.}, year={2008}, pages={2176–2184} }
 @inproceedings{orcun_kempf_uzsoy_2008, title={An Integrated Production Planning Model with Load-Dependent Lead Times and Safety Stocks}, author={Orcun, S. and Kempf, K.G. and Uzsoy, R.}, year={2008}, month={Jun} }
 @inproceedings{godinho filho_uzsoy_2008, title={Combining System Dynamics and Factory Physics to Study the Effects of Continuous Improvement on the Operating Curve}, author={Godinho Filho, M. and Uzsoy, R.}, year={2008}, month={May} }
 @article{kim_uzsoy_2008, title={Exact and heuristic procedures for capacity expansion problems with congestion}, volume={40}, ISSN={["0740-817X"]}, DOI={10.1080/07408170802322978}, abstractNote={The problem of determining an optimal capacity expansion and contraction schedule over time for production resources subject to congestion is addressed. Previous to this work non-linear constraints based on expected queue length have been used to represent congestion, whereas concave clearing functions that capture the relationship between expected throughput and expected work in process inventory in a planning period are used in this paper. A column generation procedure that uses a previously developed pseudo-polynomial-time algorithm for the single-workcenter problem to generate new columns is proposed. The fractional solution obtained by column generation is then used to construct a feasible solution. Computational experiments on randomly generated test problems show that the procedure consistently produces near-optimal solutions in modest CPU times. The column generation formulation is also used to obtain lower bounds in an exact branch-and-bound algorithm, and it is shown that this new procedure is able to solve problems that are significantly larger than those possible with previous methods.}, number={12}, journal={IIE TRANSACTIONS}, author={Kim, Sukgon and Uzsoy, Reha}, year={2008}, pages={1185–1197} }
 @article{uzsoy_velásquez_2008, title={Heuristics for minimizing maximum lateness on a single machine with family-dependent set-up times}, volume={35}, ISSN={0305-0548}, url={http://dx.doi.org/10.1016/j.cor.2006.10.003}, DOI={10.1016/j.cor.2006.10.003}, abstractNote={We address the problem of scheduling a single machine subject to family-dependent set-up times in order to minimize maximum lateness. We present a number of local improvement heuristics based on the work of previous researchers, a rolling horizon heuristic, and an incomplete dynamic programming heuristic. Extensive computational experiments on randomly generated test problems compare the performance of these heuristics. The rolling horizon procedures perform particularly well but require their parameters to be set based on problem characteristics to obtain their best performance.}, number={6}, journal={Computers & Operations Research}, publisher={Elsevier BV}, author={Uzsoy, Reha and Velásquez, Juan Diego}, year={2008}, month={Jun}, pages={2018–2033} }
 @article{kim_uzsoy_2008, title={Integrated planning of production and engineering process improvement}, volume={21}, ISSN={["0894-6507"]}, DOI={10.1109/TSM.2008.2001215}, abstractNote={The authors present a planning model to allocate equipment capacity between production that generates immediate revenue and engineering process improvement activity that results in increased future output. The benefit of engineering activity is modeled as a concave function of the total number of engineering lots processed to date, while the production facility is represented by a nonlinear clearing function capturing the nonlinear relationship between resource utilization and cycle time. We analyze the model to develop structural results and illustrate its behavior with numerical examples.}, number={3}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Kim, Sukgon and Uzsoy, Reha M.}, year={2008}, month={Aug}, pages={390–398} }
 @article{upasani_uzsoy_2008, title={Integrating a decomposition procedure with problem reduction for factory scheduling with disruptions: a simulation study}, volume={46}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207540601156215}, DOI={10.1080/00207540601156215}, abstractNote={Dispatching rules are widely used in industry because schedules obtained from optimization procedures can be difficult to implement in the face of executional uncertainties. Barua et al. (Barua, A., Narasimhan, R., Upasani, A. and Uzsoy, R., Implementing global factory schedules in the face of stochastic disruptions. Int. J. Prod. Res., 2005, 43(4), 793–818) implement global schedules obtained from an optimization-based heuristic using a dispatching rule, and outperform myopic dispatching rules in the face of disruptions. However, the computation of the global schedules is still time-consuming for realistic instances. Upasani et al. (Upasani, A., Uzsoy, R. and Sourirajan, K., A problem reduction approach for scheduling semiconductor wafer fabrication facilities. IEEE Trans. Semicon. Manuf., 2006, 19, 216–225) develop a problem reduction scheme based on load disparity between work centres, and report significant reduction in CPU times with minimal loss of solution quality in deterministic experiments. In this paper we integrate the problem-reduction scheme to obtain global schedules with the dispatching approach of Barua et al. (Barua, A., Narasimhan, R., Upasani, A. and Uzsoy, R., Implementing global factory schedules in the face of stochastic disruptions. Int. J. Prod. Res., 2005, 43(4), 793–818) in a multi-product environment with stochastic machine breakdowns and job arrivals. A simulation model of a scaled-down wafer fabrication facility is used to evaluate the performance of the proposed procedures. Results show that the integrated procedure outperforms the benchmark dispatching rules while significantly reducing computation times.}, number={21}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Upasani, A. and Uzsoy, R.}, year={2008}, month={Nov}, pages={5883–5905} }
 @article{geiger_uzsoy_2008, title={Learning effective dispatching rules for batch processor scheduling}, volume={46}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207540600993360}, DOI={10.1080/00207540600993360}, abstractNote={Batch processor scheduling, where machines can process multiple jobs simultaneously, is frequently harder than its unit-capacity counterpart because an effective scheduling procedure must not only decide how to group the individual jobs into batches, but also determine the sequence in which the batches are to be processed. We extend a previously developed genetic learning approach to automatically discover effective dispatching policies for several batch scheduling environments, and show that these rules yield good system performance. Computational results show the competitiveness of the learned rules with existing rules for different performance measures. The autonomous learning approach addresses a growing practical need for rapidly developing effective dispatching rules for these environments by automating the discovery of effective job dispatching procedures.}, number={6}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Geiger, Christopher D. and Uzsoy, Reha}, year={2008}, month={Mar}, pages={1431–1454} }
 @misc{uzsoy_2008, title={New Directions in Production Planning: A Tutorial}, author={Uzsoy, R.}, year={2008}, month={Oct} }
 @inproceedings{kefeli_uzsoy_fathi_kay_2008, title={Using a Mathematical Programming Model to Examine the Marginal Prices of Capacitated Resources}, author={Kefeli, A. and Uzsoy, R. and Fathi, Y. and Kay, M.}, year={2008}, month={Mar} }
 @article{malve_uzsoy_2007, title={A genetic algorithm for minimizing maximum lateness on parallel identical batch processing machines with dynamic job arrivals and incompatible job families}, volume={34}, ISSN={0305-0548}, url={http://dx.doi.org/10.1016/j.cor.2005.11.011}, DOI={10.1016/j.cor.2005.11.011}, abstractNote={We consider the problem of minimizing maximum lateness on parallel identical batch processing machines with dynamic job arrivals. We propose a family of iterative improvement heuristics based on previous work by Potts [Analysis of a heuristic for one machine sequencing with release dates and delivery times. Operations Research 1980;28:1436–41] and Uzsoy [Scheduling batch processing machines with incompatible job families. International Journal for Production Research 1995;33(10):2685–708] and combine them with a genetic algorithm (GA) based on the random keys encoding of Bean [Genetic algorithms and random keys for sequencing and optimization. ORSA Journal on Computing 1994;6(2):154–60]. Extensive computational experiments show that one of the proposed GAs runs significantly faster than the other, providing a good tradeoff between solution time and quality. The combination of iterative heuristics with GAs consistently outperforms the iterative heuristics on their own.}, number={10}, journal={Computers & Operations Research}, publisher={Elsevier BV}, author={Malve, Sujay and Uzsoy, Reha}, year={2007}, month={Oct}, pages={3016–3028} }
 @article{sourirajan_ozsen_uzsoy_2007, title={A single-product network design model with lead time and safety stock considerations}, volume={39}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408170600941631}, DOI={10.1080/07408170600941631}, abstractNote={Most existing network design and facility location models have focused on the trade-off between the fixed costs of locating facilities and variable transportation costs between facilities and customers. However, operational performance measures such as service levels and lead times are what motivates customers to bring business to a company and should be considered in the design of a distribution network. While some previous work has considered lead times and safety stocks separately, they are closely related in practice, since safety stocks are often set relative to the distribution of demand over the lead time. In this paper we consider a two-stage supply chain with a production facility that replenishes a single product at retailers. The objective is to locate Distribution Centers (DCs) in the network such that the sum of the location and inventory (pipeline and safety stock) costs is minimized. The replenishment lead time at the DCs depends on the volume of flow through the DC. We require the DCs to carry enough safety stock to maintain the prescribed service levels at the retailers they serve. The explicit modeling of the relationship between the flows in the network, lead times and safety stocks allows us to capture the trade-off between them. We develop a Lagrangian heuristic to obtain near-optimal solutions with reasonable computational requirements for large problem instances.}, number={5}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Sourirajan, Karthik and Ozsen, Leyla and Uzsoy, Reha}, year={2007}, month={Feb}, pages={411–424} }
 @misc{orcun_cetinkaya_uzsoy_2007, title={Determining safety stocks in the presence of workload-dependent lead times}, url={http://dx.doi.org/10.1109/wsc.2007.4419791}, DOI={10.1109/wsc.2007.4419791}, abstractNote={Most classical stochastic inventory models assume that replenishment lead times are independent of the amount of orders placed. This assumption is clearly problematic in capacitated production systems, where queueing models show that mean cycle time is a nonlinear increasing function of resource utilization. We use a simulation environment created for rapid prototyping of supply chains to examine the problem of setting safety stocks in environments with workload-dependent lead times. We show that even when extensive historical data is used, conventional approaches to setting safety stocks fail to provide the desired service level when lead times are load-dependent, and suggest directions for future research.}, journal={2007 Winter Simulation Conference}, publisher={IEEE}, author={Orcun, Seza and Cetinkaya, Sila and Uzsoy, Reha}, year={2007}, month={Dec} }
 @article{sourirajan_uzsoy_2007, title={Hybrid decomposition heuristics for solving large-scale scheduling problems in semiconductor wafer fabrication}, volume={10}, ISSN={1094-6136 1099-1425}, url={http://dx.doi.org/10.1007/s10951-006-0325-5}, DOI={10.1007/s10951-006-0325-5}, number={1}, journal={Journal of Scheduling}, publisher={Springer Science and Business Media LLC}, author={Sourirajan, Karthik and Uzsoy, Reha}, year={2007}, month={Feb}, pages={41–65} }
 @article{upasani_uzsoy_2007, title={Incorporating manufacturing lead times in joint production-marketing models: A review and some future directions}, volume={161}, ISSN={0254-5330 1572-9338}, url={http://dx.doi.org/10.1007/s10479-007-0294-x}, DOI={10.1007/s10479-007-0294-x}, number={1}, journal={Annals of Operations Research}, publisher={Springer Science and Business Media LLC}, author={Upasani, Abhijit and Uzsoy, Reha}, year={2007}, month={Dec}, pages={171–188} }
 @article{varma_uzsoy_pekny_blau_2007, title={Lagrangian heuristics for scheduling new product development projects in the pharmaceutical industry}, volume={13}, ISSN={1381-1231 1572-9397}, url={http://dx.doi.org/10.1007/s10732-007-9016-4}, DOI={10.1007/s10732-007-9016-4}, number={5}, journal={Journal of Heuristics}, publisher={Springer Science and Business Media LLC}, author={Varma, Vishal A. and Uzsoy, Reha and Pekny, Joseph and Blau, Gary}, year={2007}, month={Apr}, pages={403–433} }
 @inproceedings{orcun_uzsoy_kempf_2007, title={Lead Time Based Heuristics for Integrated Production and Safety Stock Planning}, author={Orcun, S. and Uzsoy, R. and Kempf, K.G.}, year={2007}, month={Jul} }
 @inproceedings{sourirajan_ozsen_uzsoy_2007, title={Multiproduct Network Design Model with Lead Time and Safety Stock Considerations}, author={Sourirajan, K. and Ozsen, L. and Uzsoy, R.}, year={2007}, month={Jul} }
 @article{eskigun_uzsoy_preckel_beaujon_krishnan_tew_2007, title={Outbound supply chain network design with mode selection and lead time considerations}, volume={54}, ISSN={0894-069X 1520-6750}, url={http://dx.doi.org/10.1002/nav.20205}, DOI={10.1002/nav.20205}, abstractNote={Abstract}, number={3}, journal={Naval Research Logistics}, publisher={Wiley}, author={Eskigun, Erdem and Uzsoy, Reha and Preckel, Paul V. and Beaujon, George and Krishnan, Subramanian and Tew, Jeffrey D.}, year={2007}, pages={282–300} }
 @article{orcun_asmundsson_uzsoy_clement_pekny_rardin_2007, title={Supply chain optimisation and protocol environment (SCOPE) for rapid prototyping and analysis of complex supply chains}, volume={18}, ISSN={0953-7287 1366-5871}, url={http://dx.doi.org/10.1080/09537280701417116}, DOI={10.1080/09537280701417116}, abstractNote={There is a strong need for modelling tools that allow decision makers to rapidly develop aggregate models of supply chains, including both material and information flow, that they can use to gain insights and assess alternative configurations. We present a prototype implementation of such a system and apply it to a simple supply chain for validation purposes, and to a real world case study from the consumer packaged goods industry.}, number={5}, journal={Production Planning & Control}, publisher={Informa UK Limited}, author={Orcun, S. and Asmundsson, J. M. and Uzsoy, R. and Clement, J. P. and Pekny, J. F. and Rardin, R. L.}, year={2007}, month={Jun}, pages={388–406} }
 @inproceedings{kalafatas_peeta_uzsoy_2006, title={A Common Modeling Framework for Transportation and Production Planning Problems with Congestion Phenomena}, author={Kalafatas, G. and Peeta, S. and Uzsoy, R.}, year={2006}, month={Nov} }
 @inproceedings{sourirajan_ozsen_uzsoy_2006, title={A Genetic Algorithm for a Single Product Network Design Model with Lead Time and Safety Stock Considerations}, author={Sourirajan, K. and Ozsen, L. and Uzsoy, R.}, year={2006}, month={Nov} }
 @inproceedings{sourirajan_ozsen_uzsoy_2006, title={A Multi-Product Break-Bulk Network Design Model with Lead Time and Safety Stock Considerations}, author={Sourirajan, K. and Ozsen, L. and Uzsoy, R.}, year={2006}, month={Nov} }
 @article{upasani_uzsoy_sourirajan_2006, title={A Problem Reduction Approach for Scheduling Semiconductor Wafer Fabrication Facilities}, volume={19}, ISSN={0894-6507}, url={http://dx.doi.org/10.1109/tsm.2006.873510}, DOI={10.1109/tsm.2006.873510}, abstractNote={Most scheduling procedures used in industry are based on the dispatching paradigm, where decisions are made based on the jobs available at the time the machine becomes free. While optimization-based scheduling procedures have repeatedly been shown to yield significantly better schedules under ideal circumstances, their practical implementation is hampered by high computational requirements. We present a problem reduction procedure that allows a workcenter-based global scheduling heuristic to be implemented in very low CPU times. The procedure partitions the workcenters in a fab into heavily loaded and lightly loaded classes and solves the global scheduling problem only for the heavily loaded workcenters. The proposed technique is tested on instances drawn from an International SEMATECH wafer fab model. The proposed problem reduction approach yields superior results with modest computational effort, enabling the practical use of the decomposition heuristic.}, number={2}, journal={IEEE Transactions on Semiconductor Manufacturing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Upasani, A.A. and Uzsoy, R. and Sourirajan, K.}, year={2006}, month={May}, pages={216–225} }
 @misc{deshmukh_uzsoy_2006, title={From Engineering the System to Engineering Information}, author={Deshmukh, A. and Uzsoy, R.}, year={2006}, month={Feb} }
 @inproceedings{uzsoy_velasquez_2006, title={Heuristics for Scheduling a Single Machine with Family Dependent Setup Times}, author={Uzsoy, R. and Velasquez, J.D.}, year={2006}, month={Nov} }
 @inproceedings{upasani_uzsoy_2006, title={Integrated Production Planning and Pricing with Congestion-Prone Production Resources}, author={Upasani, A. and Uzsoy, R.}, year={2006}, month={Nov} }
 @inproceedings{uzsoy_ravindran_2006, title={Integrating Production Planning and Safety Stock Determination}, author={Uzsoy, R. and Ravindran, A.}, year={2006}, month={Nov} }
 @inproceedings{mendez_uzsoy_2006, title={Juggling Tasks: Mine, Yours and Ours...}, author={Mendez, L.I. and Uzsoy, R.}, year={2006}, month={Nov} }
 @inproceedings{hwang_uzsoy_2006, title={Multiproduct Dynamic Lot Sizing with Work in Process and Congestion}, author={Hwang, S. and Uzsoy, R.}, year={2006}, month={Nov} }
 @article{geiger_uzsoy_aytuğ_2006, title={Rapid Modeling and Discovery of Priority Dispatching Rules: An Autonomous Learning Approach}, volume={9}, ISSN={1094-6136 1099-1425}, url={http://dx.doi.org/10.1007/s10951-006-5591-8}, DOI={10.1007/s10951-006-5591-8}, number={1}, journal={Journal of Scheduling}, publisher={Springer Science and Business Media LLC}, author={Geiger, Christopher D. and Uzsoy, Reha and Aytuğ, Haldun}, year={2006}, month={Feb}, pages={7–34} }
 @inproceedings{crist_uzsoy_2006, title={Scheduling Engineering and Production Lots in Wafer Fabrication}, author={Crist, K. and Uzsoy, R.}, year={2006}, month={Nov} }
 @article{asmundsson_rardin_uzsoy_2006, title={Tractable Nonlinear Production Planning Models for Semiconductor Wafer Fabrication Facilities}, volume={19}, ISSN={0894-6507}, url={http://dx.doi.org/10.1109/tsm.2005.863214}, DOI={10.1109/tsm.2005.863214}, abstractNote={We describe a simulation study of a production planning model for multistage production inventory systems that reflects the nonlinear relationship between resource utilization and lead time. The model is based on the use of clearing functions that capture the nonlinear relationship between workload and throughput. We show how these clearing functions can be estimated from empirical data using a simulation model as a surrogate for observation of the production system under study. We then examine the sensitivity of the estimated clearing function to different dispatching algorithms, different demand patterns, and production planning techniques. Computational experiments based on a scaled-down model of a semiconductor wafer fabrication facility illustrate the potential benefits of the clearing function model relative to conventional linear programming models.}, number={1}, journal={IEEE Transactions on Semiconductor Manufacturing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Asmundsson, J. and Rardin, R.L. and Uzsoy, R.}, year={2006}, month={Feb}, pages={95–111} }
 @misc{orcun_uzsoy_kempf_2006, title={Using System Dynamics Simulations to Compare Capacity Models for Production Planning}, url={http://dx.doi.org/10.1109/wsc.2006.322966}, DOI={10.1109/wsc.2006.322966}, abstractNote={While a variety of optimization formulations of production planning problems have been proposed over the last fifty years, the majority of these are based on simple models of capacity that fail to reflect the nonlinear relationship between workload and lead times induced by the queuing behavior of capacitated production resources. We use system dynamics simulations of a simple capacitated production system to examine the performance of several different capacity models that yield load-dependent lead times, and relate these models to those used in system dynamics models of production systems}, journal={Proceedings of the 2006 Winter Simulation Conference}, publisher={IEEE}, author={Orcun, Seza and Uzsoy, Reha and Kempf, Karl}, year={2006}, month={Dec} }
 @inproceedings{uzsoy_hwang_2005, title={A Dynamic Lot Sizing Model with Congestion}, author={Uzsoy, R. and Hwang, S.}, year={2005}, month={Oct} }
 @inproceedings{turkseven_uzsoy_2005, title={Computational Comparison of Linear and Nonlinear Production Planning Formulations}, author={Turkseven, C. and Uzsoy, R.}, year={2005}, month={Nov} }
 @misc{uzsoy_2005, title={E-business in the Supply Chain: Past, Present and Future}, author={Uzsoy, R.}, year={2005}, month={Dec} }
 @article{aytug_lawley_mckay_mohan_uzsoy_2005, title={Executing production schedules in the face of uncertainties: A review and some future directions}, volume={161}, ISSN={0377-2217}, url={http://dx.doi.org/10.1016/j.ejor.2003.08.027}, DOI={10.1016/j.ejor.2003.08.027}, abstractNote={We review the literature on executing production schedules in the presence of unforeseen disruptions on the shop floor. We discuss a number of issues related to problem formulation, and discuss the functions of the production schedule in the organization and provide a taxonomy of the different types of uncertainty faced by scheduling algorithms. We then review previous research relative to these issues, and suggest a number of directions for future work in this area.}, number={1}, journal={European Journal of Operational Research}, publisher={Elsevier BV}, author={Aytug, Haldun and Lawley, Mark A. and McKay, Kenneth and Mohan, Shantha and Uzsoy, Reha}, year={2005}, month={Feb}, pages={86–110} }
 @article{barua_raghavan_upasani_uzsoy *_2005, title={Implementing global factory schedules in the face of stochastic disruptions}, volume={43}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207540412331282024}, DOI={10.1080/00207540412331282024}, abstractNote={The problem of implementing global factory schedules developed from an optimization-based heuristic in a manufacturing facility with executional uncertainties in the form of machine failures is considered. A simple procedure in which jobs are dispatched on the shop floor is proposed based on their start times in the global schedule is proposed. The performance of the proposed procedure relative to a number of well-known dispatching rules is evaluated using a simulation model of a scaled-down semiconductor wafer fabrication facility. Results indicate that the procedure combining the global schedule and dispatching outperforms the benchmark dispatching rules in terms of several performance measures as long as the level of variability in the system is compatible with the frequency of rescheduling.}, number={4}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Barua, A. and Raghavan, N. and Upasani, A. and Uzsoy *, R.}, year={2005}, month={Feb}, pages={793–818} }
 @misc{uzsoy_2005, title={Modeling Capacity in Optimization Models for Production Planning: A Review and Some New Developments}, author={Uzsoy, R.}, year={2005}, month={Apr} }
 @misc{uzsoy_2005, title={Modelling Capacity in Production and Supply Chain Planning}, author={Uzsoy, R.}, year={2005}, month={Apr} }
 @misc{uzsoy_2005, title={Nonlinear Models for Production Planning in Capacitated Production-Inventory Systems}, author={Uzsoy, R.}, year={2005}, month={Jun} }
 @article{eskigun_uzsoy_preckel_beaujon_krishnan_tew_2005, title={Outbound supply chain network design with mode selection, lead times and capacitated vehicle distribution centers}, volume={165}, ISSN={0377-2217}, url={http://dx.doi.org/10.1016/j.ejor.2003.11.029}, DOI={10.1016/j.ejor.2003.11.029}, abstractNote={Most distribution network design models considered to date have focused on minimizing fixed costs of facility location and transportation costs. Measures of customer satisfaction driven by the operational dynamics such as lead times have seldom been considered. We consider the design of an outbound supply chain network considering lead times, location of distribution facilities and choice of transportation mode. We present a Lagrangian heuristic that gives excellent solution quality in reasonable computational time. Scenario analyses are conducted on industrial data using this algorithm to observe how the supply chain behaves under different parameter values.}, number={1}, journal={European Journal of Operational Research}, publisher={Elsevier BV}, author={Eskigun, Erdem and Uzsoy, Reha and Preckel, Paul V. and Beaujon, George and Krishnan, Subramanian and Tew, Jeffrey D.}, year={2005}, month={Aug}, pages={182–206} }
 @article{akçalı_üngör_uzsoy_2005, title={Short-term capacity allocation problem with tool and setup constraints}, volume={52}, ISSN={0894-069X 1520-6750}, url={http://dx.doi.org/10.1002/nav.20112}, DOI={10.1002/nav.20112}, abstractNote={Abstract}, number={8}, journal={Naval Research Logistics}, publisher={Wiley}, author={Akçalı, Elif and Üngör, Alper and Uzsoy, Reha}, year={2005}, month={Dec}, pages={754–764} }
 @inbook{uzsoy_2005, title={Supply Chain Management and Health-Care Delivery: Pursuing a Systems-Level Understanding}, booktitle={Building a Better Delivery System: A New Engineering/Health Care Partnership}, publisher={National Academies of Engineering}, author={Uzsoy, R.}, editor={Reid, P.P. and Compton, W.D. and Grossman, J.H. and Fanjiang, G.Editors}, year={2005} }
 @misc{uzsoy_2004, title={Center of Excellence in Competitive Global Logistics}, author={Uzsoy, R.}, year={2004}, month={May} }
 @misc{uzsoy_2004, title={Modelling Capacity in Production and Supply Chain Planning}, author={Uzsoy, R.}, year={2004}, month={Jul} }
 @misc{uzsoy_2004, title={Modelling Capacity in Production and Supply Chain Planning}, author={Uzsoy, R.}, year={2004}, month={Apr} }
 @misc{uzsoy_2004, title={Modelling Capacity in Production and Supply Chain Planning}, author={Uzsoy, R.}, year={2004}, month={Mar} }
 @misc{uzsoy_2004, title={Supply Chain Survival Strategies: Eat or Be Eaten}, author={Uzsoy, R.}, year={2004}, month={Sep} }
 @misc{uzsoy_2004, title={Transportation, Distribution and Logistics in Indiana}, author={Uzsoy, R.}, year={2004}, month={Sep} }
 @misc{uzsoy_2004, title={Transportation, Distribution and Logistics in Indiana}, author={Uzsoy, R.}, year={2004}, month={Apr} }
 @misc{asmundsson_uzsoy_2003, title={Capacity Modelling in Production and Supply Chain Planning}, author={Asmundsson, J. and Uzsoy, R.}, year={2003}, month={Jan} }
 @article{aytug_kempf_uzsoy_2003, title={Measures of subproblem criticality in decomposition algorithms for shop scheduling}, volume={41}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/0020754021000037856}, DOI={10.1080/0020754021000037856}, abstractNote={Work centre-based decomposition approaches, especially variants of the Shifting Bottleneck algorithm, have been very successful in solving job-shop-scheduling problems. These methods decompose the problem into subproblems involving a single work centre (usually a single machine), which they solve sequentially. We propose new measures of subproblem criticality and show via computational experiments that several of these provide solutions comparable in quality with those obtained from previous work in substantially less central processing unit time.}, number={5}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Aytug, H. and Kempf, K. and Uzsoy, R.}, year={2003}, month={Jan}, pages={865–882} }
 @misc{asmundsson_uzsoy_2003, title={Modelling in Production and Supply Chain Planning: History and a New Approach}, author={Asmundsson, J. and Uzsoy, R.}, year={2003}, month={Feb} }
 @article{aytug_barua_lawley_uzsoy_2003, title={Observations on the interactions among deadlock avoidance policies and dispatching rules in automated manufacturing systems}, volume={41}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207540210163955}, DOI={10.1080/00207540210163955}, abstractNote={In automated manufacturing systems, deadlock avoidance policies guarantee deadlock-free operation while performance controllers, such as dispatching rules, attempt to achieve performance thresholds. In an automated system, dispatching rules must work within the constraints imposed by the deadlock avoidance policy in order to assure continuing system operation, and thus, the deadlock avoidance logic defines the decision space over which the dispatching rule can work. This paper investigates the interactions that arise between deadlock avoidance flexibility and the effectiveness of dispatching rules in achieving good system performance. Two major findings are that the positive effects of intelligent dispatching are highly influenced by the flexibility of the deadlock avoidance policy, and that a naÿve dispatching rule can sometimes achieve better system performance under an inflexible deadlock avoidance policy.}, number={1}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Aytug, H. and Barua, A. and Lawley, M. and Uzsoy, R.}, year={2003}, month={Jan}, pages={81–95} }
 @misc{uzsoy_2003, title={Supply Chain Management: Pursuing a System-Level Understanding}, author={Uzsoy, R.}, year={2003}, month={Mar} }
 @inproceedings{orcun_asmundsson_pekny_rardin_uzsoy_2003, title={Supply Chain Optimization and Protocol Environment (SCOPE) for Rapid Prototyping of Supply Chains}, booktitle={Proceedings of the Conference on Industrial Engineering and Production Management}, author={Orcun, S. and Asmundsson, J. and Pekny, J. and Rardin, R.L. and Uzsoy, R.}, year={2003}, month={May} }
 @article{wang_uzsoy_2002, title={A genetic algorithm to minimize maximum lateness on a batch processing machine}, volume={29}, ISSN={0305-0548}, url={http://dx.doi.org/10.1016/s0305-0548(01)00031-4}, DOI={10.1016/s0305-0548(01)00031-4}, abstractNote={We consider the problem of minimizing maximum lateness on a batch processing machine in the presence of dynamic job arrivals. The batch processing machine can process up to B jobs simultaneously, and the processing time of a batch is given by that of the job with the longest processing time in the batch. We adapt a dynamic programming algorithm from the literature to determine whether a due-date feasible batching exists for a given job sequence. We then combine this algorithm with a random keys encoding scheme to develop a genetic algorithm for this problem. Computational experiments indicate that this algorithm has excellent average performance with reasonable computational burden. In this paper we address the problem of scheduling a single batch processing machine subject to dynamic job arrivals, which generalizes a number of classical single-machine models from scheduling theory (Pinedo. Scheduling theory, algorithms, and systems. Englewood Cliffs, NJ: Prentice-Hall, 1995.) Batch processing machines, where a number of jobs are processed simultaneously as a batch, are quite common in the metalworking and microelectronics industries. Although an extensive literature on several scheduling models for this type of machine has developed in the last decade, there has been relatively little work on models that consider jobs arriving at the machine dynamically over time. However, such dynamic models are an essential component of decomposition heuristics (Ovacik, Uzsoy. Decomposition methods for complex factory scheduling problems. Massachusetts: Kluwer Academic Publishers, 1997.) used to schedule the factories within which the batch processing machines form an individual workcenter. This paper builds on results developed in prior work (Lee et al. Operations Research 1992;40:764–75.) and (Uzsoy. International Journal of Production Research 1995;33:2605–708.) to develop an effective genetic algorithm (Goldberg. Genetic algorithms in search, optimization and machine learning. Reading, MA: Addison-Wesley, 1989.) for solving this provably intractable scheduling problem. Our procedure combines an optimization algorithm to evaluate job sequences with a random key representation that guarantees feasible solutions after crossover operations. Extensive computational experiments show that it consistently obtains high-quality solutions in modest CPU times.}, number={12}, journal={Computers & Operations Research}, publisher={Elsevier BV}, author={Wang, Cheng-Shuo and Uzsoy, Reha}, year={2002}, month={Oct}, pages={1621–1640} }
 @misc{akcali_uzsoy_hiscock_moser_teyner_2002, title={Alternative loading and dispatching policies for furnace operations in semiconductor manufacturing: a comparison by simulation}, url={http://dx.doi.org/10.1109/wsc.2000.899121}, DOI={10.1109/wsc.2000.899121}, abstractNote={In semiconductor manufacturing, furnaces are used for diffusion and deposition operations. A furnace is a batch processing machine, which can simultaneously process a number of lots together as a batch. Whenever a furnace becomes available, scheduling the next batch involves decisions on both which operation to process next (dispatching policy) and how many lots to put into the batch (loading policy). A simulation model of a wafer fabrication facility is used to examine the effects of different loading and dispatching policies for diffusion operations. Results indicate that the loading policy has a significant effect on the average diffusion flow time as well as the overall cycle time of the products, whereas dispatching policy has a less significant effect. We show that the production volume of a product should be considered in setting the minimum number of lots needed to start a batch. We suggest that the diffusion flow time for a low volume product can be reduced by releasing the product in batches or by setting the minimum batch size such that the work-in-process of the product can be moved faster.}, journal={2000 Winter Simulation Conference Proceedings (Cat. No.00CH37165)}, publisher={IEEE}, author={Akcali, E. and Uzsoy, R. and Hiscock, D.G. and Moser, A.L. and Teyner, T.J.}, year={2002}, month={Nov} }
 @misc{uzsoy_2002, title={Capacity and Congestion in Modelling Supply Chains}, author={Uzsoy, R.}, year={2002}, month={Feb} }
 @misc{asmundsson_rardin_uzsoy_2002, title={Compact Nonlinear Capacity Models for Supply Chain Planning}, author={Asmundsson, J. and Rardin, R.L. and Uzsoy, R.}, year={2002}, month={Jul} }
 @inproceedings{aytug_lawley_mckay_mohan_uzsoy_2002, title={Executing Production Schedules in the Face of Uncertainties}, author={Aytug, H. and Lawley, M.A. and McKay, K.N. and Mohan, S. and Uzsoy, R.}, year={2002}, month={Nov} }
 @misc{asmundsson_rardin_uzsoy_2002, title={Modeling Capacity in Production and Supply Chain Planning}, author={Asmundsson, J. and Rardin, R.L. and Uzsoy, R.}, year={2002}, month={Dec} }
 @misc{asmundsson_uzsoy_2002, title={Modeling Cpacity in Production and Supply Chain Planning}, author={Asmundsson, J.M. and Uzsoy, R.}, year={2002}, month={Nov} }
 @misc{orcun_pekny_asmundsson_uzsoy_2002, title={SCOPE for Rapid Prototyping of Complex Supply Chains}, author={Orcun, S. and Pekny, J. and Asmundsson, J. and Uzsoy, R.}, year={2002}, month={Sep} }
 @misc{uzsoy_2002, title={Supply Chain Management: History and Trends}, author={Uzsoy, R.}, year={2002}, month={Nov} }
 @article{akcalt_davis_hamlin_mccullough_teyner_uzsoy_2001, title={A decision support system for spare parts management in a wafer fabrication facility}, volume={14}, ISSN={0894-6507}, url={http://dx.doi.org/10.1109/66.909657}, DOI={10.1109/66.909657}, abstractNote={We present a decision support system for spare parts management in a wafer fabrication facility. The system is based on an analytical stochastic inventory model, which calculates the reorder level and quantity for each part to attain a specified service level. Results from our simulation study indicate that the policies suggested by the system either improve the service level or reduce the operating cost.}, number={1}, journal={IEEE Transactions on Semiconductor Manufacturing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Akcalt, E. and Davis, M. and Hamlin, R.D. and McCullough, T. and Teyner, T. and Uzsoy, R.}, year={2001}, pages={76–78} }
 @inbook{musselman_uzsoy_2001, title={Advanced Planning and Scheduling for Manufacturing}, booktitle={Handbook of Industrial Engineering}, publisher={John Wiley}, author={Musselman, K. and Uzsoy, R.}, editor={Salvendy, G.Editor}, year={2001} }
 @misc{asmundsson_orcun_rardin_uzsoy_2001, place={Los Angeles, CA}, title={Compact Nonlinear Capacity Models for Supply Chains}, author={Asmundsson, J. and Orcun, S. and Rardin, R.L. and Uzsoy, R.}, year={2001}, month={Feb} }
 @article{akcalt_nemoto_uzsoy_2001, title={Cycle-time improvements for photolithography process in semiconductor manufacturing}, volume={14}, ISSN={0894-6507}, url={http://dx.doi.org/10.1109/66.909654}, DOI={10.1109/66.909654}, abstractNote={Cycle-time reduction is of great importance to semiconductor manufacturers. Photolithography, being one of the most repeated processes, is an area where substantial improvements can be made. We investigate the effects of various process control mechanisms for photolithography on the cycle-time at the process and at the overall fab via a simulation study. Test run policy at the photolithography station, test run frequency, duration of inspection, and machine dedication policy for the equipment are the factors we consider. Equipment down time due to preventive or breakdown maintenance and rework rates are also taken into account. Parallel testing, where test wafer is inspected while the lot is being processed, is the best policy in terms of cycle-time performance. Long inspection time and infrequent, long down times have the most adverse effects, but flexible machine assignment may reduce the impact of down times. Test run frequency is only significant for serial testing, where processing of the lot is not finished until the failed test wafer is stripped and reworked.}, number={1}, journal={IEEE Transactions on Semiconductor Manufacturing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Akcalt, E. and Nemoto, K. and Uzsoy, R.}, year={2001}, pages={48–56} }
 @inproceedings{aytug_lawley_mohan_uzsoy_2001, title={Executing Production Schedules In The Face Of Uncertainties: A Brief Review And Some Future Directions}, booktitle={Proceedings of the Conference on Industrial Engineering and Production Management}, author={Aytug, H. and Lawley, M.A. and Mohan, S. and Uzsoy, R.}, year={2001}, month={Aug} }
 @article{rardin_uzsoy_2001, title={Experimental Evaluation of Heuristic Optimization Algorithms: A Tutorial}, volume={7}, ISSN={1381-1231}, url={http://dx.doi.org/10.1023/a:1011319115230}, DOI={10.1023/a:1011319115230}, number={3}, journal={Journal of Heuristics}, publisher={Springer Science and Business Media LLC}, author={Rardin, Ronald L. and Uzsoy, Reha}, year={2001}, month={May}, pages={261–304} }
 @article{horiguchi_raghavan_uzsoy_venkateswaran_2001, title={Finite-capacity production planning algorithms for a semiconductor wafer fabrication facility}, volume={39}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207540010010253}, DOI={10.1080/00207540010010253}, abstractNote={We consider the problem of production planning for a semiconductor wafer fabrication facility producing application-specific integrated circuits (ASICS) to customer order. Using a simple planning algorithm based on forward scheduling for WIP and backward scheduling for new orders, the effects of the level of detail at which the production process is modelled was examined. A simulation study showed that considering all near-constraint workcentres explicitly as having finite-capacity gives the best results. Also examined were the effects of undercapacity planning, and it was shown that when coupled with a shop-floor scheduling procedure driven by the planned completion date rather than customer due dates, significant improvements in both delivery performance and system predictability were obtained.}, number={5}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Horiguchi, K. and Raghavan, N. and Uzsoy, R and Venkateswaran, S.}, year={2001}, month={Jan}, pages={825–842} }
 @misc{uzsoy_2001, title={From Finite Capacity to Supply Chain Management}, author={Uzsoy, R.}, year={2001}, month={Dec} }
 @inproceedings{akcali_uzsoy_2000, title={A Sequential Solution Methodology for Capacity Allocation and Lot Scheduling Problems at Photolithography}, booktitle={Proceedings of the 26th International Electronics Manufacturing Technology Symposium}, author={Akcali, E. and Uzsoy, R.}, year={2000}, month={Oct} }
 @misc{uzsoy_2000, title={A review of: “Deterministic scheduling theory” R. Gary Parker Chapman and Hall, London 1995, Hardback, 290 pages, ISBN (HB) 0-412-99681-2}, volume={32}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408170008967434}, DOI={10.1080/07408170008967434}, number={8}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Uzsoy, Rcha}, year={2000}, month={Aug}, pages={767–768} }
 @misc{uzsoy_2000, title={A review of: “Operations scheduling with applications in manufacturing and services”M. Pinedo and X. Chao McGraw-Hill, New York 1999, 310 pages, ISBN 0-07-289779-1}, volume={32}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408170008967435}, DOI={10.1080/07408170008967435}, number={8}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Uzsoy, Reha}, year={2000}, month={Aug}, pages={768–770} }
 @article{demirkol_uzsoy_2000, title={Decomposition methods for reentrant flow shops with sequence-dependent setup times}, volume={3}, ISSN={1094-6136 1099-1425}, url={http://dx.doi.org/10.1002/(sici)1099-1425(200005/06)3:3<155::aid-jos39>3.0.co;2-e}, DOI={10.1002/(sici)1099-1425(200005/06)3:3<155::aid-jos39>3.0.co;2-e}, abstractNote={We consider the problem of scheduling a reentrant flow shop with sequence-dependent setup times to minimize maximum lateness. We develop a series of decomposition methods (DMs) exploring the importance of components such as subproblem solution method, bottleneck identification and reoptimization method on the solution time/quality tradeoff. Based on these results, we propose an enhanced DM which gives promising results for these difficult scheduling problems. Our results also yield interesting insights into the strengths and limitations of DMs. Copyright © 2000 John Wiley & Sons, Ltd.}, number={3}, journal={Journal of Scheduling}, publisher={Wiley}, author={Demirkol, Ebru and Uzsoy, Reha}, year={2000}, month={May}, pages={155–177} }
 @article{kempf_uzsoy_smith_gary_2000, title={Evaluation and comparison of production schedules}, volume={42}, ISSN={0166-3615}, url={http://dx.doi.org/10.1016/s0166-3615(99)00071-8}, DOI={10.1016/s0166-3615(99)00071-8}, abstractNote={The understanding of what constitutes a “good” production schedule is central to the development and evaluation of automated scheduling systems and their implementation in real-world factories. In this paper, we provide a definition of a schedule and discuss potential uses for a schedule within the organization. We then describe a number of different considerations that must be taken into account when assessing the quality of a schedule, and discuss their implications for the design and implementation of scheduling systems.}, number={2-3}, journal={Computers in Industry}, publisher={Elsevier BV}, author={Kempf, Karl and Uzsoy, Reha and Smith, Stephen and Gary, Kevin}, year={2000}, month={Jun}, pages={203–220} }
 @article{ovacik_rajagopalan_uzsoy_2000, title={Integrating Interval Estimates of Global Optima and Local Search Methods for Combinatorial Optimization Problems}, volume={6}, ISSN={1381-1231}, url={http://dx.doi.org/10.1023/a:1009669326107}, DOI={10.1023/a:1009669326107}, number={4}, journal={Journal of Heuristics}, publisher={Springer Science and Business Media LLC}, author={Ovacik, Irfan M. and Rajagopalan, Srikanth and Uzsoy, Reha}, year={2000}, month={Sep}, pages={481–500} }
 @inproceedings{aytug_kempf_uzsoy_2000, title={Integrating Machine Learning and Decomposition Heuristics for Complex Factory Scheduling Problems}, booktitle={Proceedings of the NSF Design and Manufacturing Conference}, author={Aytug, H. and Kempf, K.G. and Uzsoy, R.}, year={2000}, month={Jan} }
 @article{uzsoy_wang_2000, title={Performance of decomposition procedures for job shop scheduling problems with bottleneck machines}, volume={38}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/002075400188843}, DOI={10.1080/002075400188843}, abstractNote={Decomposition procedures for job shop scheduling problems, such as the shifting bottleneck (SB) procedure, have shown promising results for a variety of shop environments. However, they have primarily been tested using problems where all machines are identical in terms of processing time distribution. Many practical scheduling problems involve bottleneck machines which become the focus of scheduling efforts, as suggested by the theory of constraints. In this paper we examine the performance of several variants of SB, some of which can be interpreted as naive implementations of the TOC approach to scheduling. Our results show that both the solution time and quality of SB methods improve markedly when bottleneck workcentres are present. However, scheduling bottleneck machines optimally and using simple rules at other machines leads to poor performance unless the workload of the bottlenecks significantly exceeds that of the non-bottleneck machines.}, number={6}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Uzsoy, Reha and Wang, Cheng-Shuo}, year={2000}, month={Apr}, pages={1271–1286} }
 @article{nemoto_akcali_uzsoy_2000, title={Quantifying the benefits of cycle time reduction in semiconductor wafer fabrication}, volume={23}, ISSN={1521-334X}, url={http://dx.doi.org/10.1109/6104.827525}, DOI={10.1109/6104.827525}, abstractNote={In recent years, semiconductor manufacturing has become increasingly complex due to device size reduction. Hence the manufacturing cycle time, also called turn around time (TAT), which is defined as the time required from wafer input through probing test, becomes longer year by year. This renders the delay between the occurrence of process defects and their detection a significant problem. On the other hand, customer demands for faster delivery are increasing as product life cycles are getting shorter. Hence, TAT reduction is important for semiconductor manufacturers not only to satisfy customer requirements, but also to remain competitive in their market. This paper examines the financial benefits of TAT reduction in ramping up a new process using stochastic simulation. Results indicate that reducing TAT in the ramp-up phase is important, and that even small reductions can have significant effects over the life cycle of a process.}, number={1}, journal={IEEE Transactions on Electronics Packaging Manufacturing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Nemoto, K. and Akcali, E. and Uzsoy, R.M.}, year={2000}, month={Jan}, pages={39–47} }
 @inproceedings{eskigun_preckel_uzsoy_2000, title={Supply Chain Design for Firms with Product Recovery}, booktitle={Proceedings of the NSF Design and Manufacturing Conference}, author={Eskigun, E. and Preckel, P.V. and Uzsoy, R.}, year={2000}, month={Jan} }
 @misc{uzsoy_2000, title={Trends and Issues in Extended Enterprise Systems}, author={Uzsoy, R.}, year={2000}, month={Oct} }
 @inproceedings{horiguchi_uzsoy_venkateswaran_1999, title={A Fast Approximation Algorithm for Cycle Time Estimation in Wafer Fabrication Facilities}, booktitle={Proceedings of the 8th Industrial Engineering Research Conference}, author={Horiguchi, K. and Uzsoy, R. and Venkateswaran, S.}, year={1999}, month={May} }
 @misc{aytug_uzsoy_1999, title={A Scheduling Architecture for Semiconductor Manufacturing}, author={Aytug, H. and Uzsoy, R.}, year={1999}, month={Nov} }
 @misc{uzsoy_1999, title={A review of: “The Planning and Scheduling of Production Systems” Edited by A. Arbita and S.E. Elmaghraby Chapman and Hall, 1997, 367 pages, ISBN 0-412-61020-5}, volume={31}, DOI={10.1080/07408179908969819}, number={2}, journal={IIE Transactions}, author={Uzsoy, R.}, year={1999}, pages={190–193} }
 @misc{uzsoy_1999, title={Current and Future Trends and Scheduling Semiconductor Manufacturing Systems}, author={Uzsoy, R.}, year={1999}, month={Mar} }
 @article{woo_uzsoy_ghafoor_1999, title={Media Streams Scheduling for Synchronization in Distributed Multimedia Systems}, volume={56}, ISSN={0743-7315}, url={http://dx.doi.org/10.1006/jpdc.1998.1526}, DOI={10.1006/jpdc.1998.1526}, abstractNote={In this paper, we consider the problem of multimedia synchronization based on scheduling the transmission of multimedia documents in a networked environment. Assuming channels with different bandwidth and delay characteristics are established between the multimedia server and the client, we formulate the scheduling problem to ensure interstream and intrastream synchronization as a parallel processor scheduling problem. Since the heterogeneous parallel processor scheduling problem is NP-hard, we propose two heuristic algorithms with time complexity ofO(nlogn+nm), wherenis the number of data units to be scheduled andmthe number of channels available. We also develop an enumerative algorithm to obtain the exact solutions. Extensive computational simulations reveal that the heuristics consistently obtain near-optimal solutions. From the simulation results, we also identify special structures of multimedia documents along with characteristics of the available channels which affect the relative performance of the algorithms.}, number={3}, journal={Journal of Parallel and Distributed Computing}, publisher={Elsevier BV}, author={Woo, Miae and Uzsoy, Reha and Ghafoor, Arif}, year={1999}, month={Mar}, pages={272–295} }
 @article{lee_uzsoy_1999, title={Minimizing makespan on a single batch processing machine with dynamic job arrivals}, volume={37}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/002075499192020}, DOI={10.1080/002075499192020}, abstractNote={We consider the problem of minimizing makespan Cmax on a single batch processing machine in the presence of dynamic job arrivals. The batch processing machine can process up to B jobs simultaneously. The processing time of a batch is given by the processing time of the longest job in the batch. We present polynomial and pseudopolynomial-time algorithms for several special cases, develop efficient heuristics for the general problem and evaluate their performance through extensive computational experiments. Our results indicate that several of the heuristics have an excellent average performance with a modest computational burden.}, number={1}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Lee, C.-Y. and Uzsoy, R.}, year={1999}, month={Jan}, pages={219–236} }
 @article{meacham_uzsoy_venkatadri_1999, title={Optimal disassembly configurations for single and multiple products}, volume={18}, ISSN={0278-6125}, url={http://dx.doi.org/10.1016/s0278-6125(00)87634-7}, DOI={10.1016/s0278-6125(00)87634-7}, abstractNote={This paper considers the problem of determining optimal disassembly configurations for single and multiple products, that is, which assemblies and subassemblies to disassemble and which to leave intact. The paper first examines the problem of determining revenue-maximizing disassembly configurations for a single product using the hierarchical product tree representation, and develops a linear time algorithm for its solution. This algorithm is then extended to the case where fixed costs may be associated with disassembly of some nodes in the product tree. Finally, the problem of meeting a specified demand for recovered components and subassemblies from an available inventory of recovered products, where disassembly capacity is limited and products may have common components, is formulated as an optimization problem. A column-generation algorithm for this problem is presented that is capable of solving reasonably sized problems in a few seconds of CPU time on average.}, number={5}, journal={Journal of Manufacturing Systems}, publisher={Elsevier BV}, author={Meacham, Anu and Uzsoy, Reha and Venkatadri, Uday}, year={1999}, month={Jan}, pages={311–322} }
 @article{mehta_uzsoy_1999, title={Predictable scheduling of a single machine subject to breakdowns}, volume={12}, ISSN={0951-192X 1362-3052}, url={http://dx.doi.org/10.1080/095119299130443}, DOI={10.1080/095119299130443}, abstractNote={The predictive production schedule has two important functions; allocating shop resources to the different jobs to optimize some measure of shop performance and serving as a basis for planning activities such as material procurement, preventive maintenance and delivery of orders to external or internal customers. This schedule is modified during execution on the occurrence of disruptions such as machine breakdowns. The schedule modification process may delay or render infeasible the execution of activities planned on the basis of the predictive schedule. Thus it is of interest to develop predictive schedules which can absorb disruptions without affecting planned activities while maintaining high shop performance. A predictable scheduling approach is presented, where the predictive schedule is built with such objectives. The effects of disruptions on planned activities are measured by the difference between planned and realized job completion times. The specific scheduling model considered is minimizing ma...}, number={1}, journal={International Journal of Computer Integrated Manufacturing}, publisher={Informa UK Limited}, author={Mehta, Sanjay V. and Uzsoy, R.}, year={1999}, month={Jan}, pages={15–38} }
 @article{o'donovan_uzsoy_mckay_1999, title={Predictable scheduling of a single machine with breakdowns and sensitive jobs}, volume={37}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/002075499189745}, DOI={10.1080/002075499189745}, abstractNote={Production schedules released to the shop floor have two important functions: allocating shop resources to different jobs to optimize some measure of shop performance and serving as a basis for planning external activities such as material procurement, preventive maintenance and delivery of orders to customers. Schedule modification may delay or render infeasible the execution of external activities planned on the basis of the predictive schedule. Thus it is of interest to develop predictive schedules that can absorb disruptions without affecting planned external activities while maintaining high shop performance. We present a predictable scheduling approach, that inserts additional idle time into the schedule to absorb the impacts of breakdowns. The effects of disruptions on planned support activities are measured by the deviations of job completion times in the realized schedule from those in the predictive schedule. We apply our approach to minimizing total tardiness on a single machine with stochastic...}, number={18}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={O'Donovan, Ronan and Uzsoy, Reha and McKay, Kenneth N.}, year={1999}, month={Dec}, pages={4217–4233} }
 @inbook{uzsoy_1999, title={Production Engineering}, booktitle={McGraw-Hill Encyclopedia of Science and Technology}, publisher={McGraw-Hill}, author={Uzsoy, R.}, year={1999} }
 @misc{uzsoy_1998, title={A Senior Design Course with Industrial Experience}, author={Uzsoy, R.}, year={1998}, month={Apr} }
 @article{toktay_uzsoy_1998, title={A capacity allocation problem with integer side constraints}, volume={109}, ISSN={0377-2217}, url={http://dx.doi.org/10.1016/s0377-2217(98)80011-8}, DOI={10.1016/s0377-2217(98)80011-8}, abstractNote={We address a capacity allocation problem arising as a subproblem of an artificial intelligence-based scheduling system for a semiconductor wafer fabrication facility. Tooling constraints, setup considerations and differences in machine capabilities are taken into account. Focusing on the objectives of maximizing throughput and minimizing deviation from predetermined production goals, we formulate the problem as a maximum flow problem on a bipartite network with integer side constraints and develop efficient heuristics which obtain near-optimal solutions in negligible computation time. The type of network flow problem we study has not been addressed in the literature to date and is of considerable theoretical interest. From a practical point of view, the network flow model of the problem and the algorithms developed for its solution are applicable to a wide range of production settings.}, number={1}, journal={European Journal of Operational Research}, publisher={Elsevier BV}, author={Toktay, L.Beril and Uzsoy, Reha}, year={1998}, month={Aug}, pages={170–182} }
 @article{demirkol_mehta_uzsoy_1998, title={Benchmarks for shop scheduling problems}, volume={109}, ISSN={0377-2217}, url={http://dx.doi.org/10.1016/s0377-2217(97)00019-2}, DOI={10.1016/s0377-2217(97)00019-2}, abstractNote={In this paper we present extensive sets of randomly generated test problems for the problems of minimizing makespan (Cmax) and maximum lateness (Lmax) in flow shops and job shops. The 600 problems include three different types of routings, four different due date configurations and a variety of problem sizes. The problems, as well as the best existing solution and a lower bound on the optimal value are available on the world-wide web.}, number={1}, journal={European Journal of Operational Research}, publisher={Elsevier BV}, author={Demirkol, Ebru and Mehta, Sanjay and Uzsoy, Reha}, year={1998}, month={Aug}, pages={137–141} }
 @article{avramidis_healy_uzsoy_1998, title={Control of a batch-processing machine: A computational approach}, volume={36}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/002075498192355}, DOI={10.1080/002075498192355}, abstractNote={Batch processing machines, where a number of jobs are processed simultaneously as a batch, occur frequently in semiconductor manufacturing environments, particularly at diffusion in wafer fabrication and at burn-in in final test. In this paper we consider a batch-processing machine subject to uncertain (Poisson) job arrivals. Two different cases are studied: (1) the processing times of batches are independent and identically distributed (IID), corresponding to a diffusion tube; and (2) the processing time of each batch is the maximum of the processing times of its constituent jobs, where the processing times of jobs are IID, modelling a burn-in oven. We develop computational procedures to minimize the expected long-run-average number of jobs in the system under a particular family of control policies. The control policies considered are threshold policies, where processing of a batch is initiated once a certain number of jobs have accumulated in the system. We present numerical examples of our methods and...}, number={11}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Avramidis, A. N. and Healy, K.J. and Uzsoy, R.}, year={1998}, month={Nov}, pages={3167–3181} }
 @inproceedings{demirkol_uzsoy_wang_1998, place={Istanbul, Turkey}, title={Decomposition Procedures for Scheduling Complex Job Shops}, booktitle={Proceedings of the Sixth International Workshop on Project Management and Scheduling}, author={Demirkol, E. and Uzsoy, R. and Wang, C.S.}, year={1998}, month={Jul} }
 @inproceedings{hughes_neudeck_uzsoy_1998, place={Austin, TX}, title={Effects of epitaxial silicon technology on the manufacturing performance of wafer fabrication lines}, url={http://dx.doi.org/10.1109/iemt.1998.731090}, DOI={10.1109/iemt.1998.731090}, abstractNote={This paper evaluates the manufacturing benefits of silicon selective epitaxial growth (SEG) as a front-end device isolation fabrication process. The technology is evaluated in two different ways. First, the cost of ownership (COO) of the equipment is used to obtain a cost of process (COP) for SEG and compared to the current alternatives, which are local oxidation of silicon (LOCOS) and shallow trench isolation (STI). Results of the processes, up to the point where the CMOS MOSFETs are produced, show that cost reductions using SEG was more than 22% compared to LOCOS and 49% compared to STI. The second evaluation approach examines the effects of the three processes on the mean and variance of fabrication cycle time using queuing network models. These results indicate that the mean cycle time for the portion of the line being considered could drop by as much as one third when the dielectric isolation by SEG (DI-SEG) process is implemented. Significant increases in line yield may also result.}, booktitle={Twenty Third IEEE/CPMT International Electronics Manufacturing Technology Symposium (Cat. No.98CH36205)}, publisher={IEEE}, author={Hughes, J.C. and Neudeck, G.W. and Uzsoy, R.}, year={1998} }
 @inproceedings{rardin_uzsoy_1998, title={Empirical Evaluation of Heuristics: A Tutorial}, author={Rardin, R.L. and Uzsoy, R.}, year={1998}, month={Apr} }
 @misc{uzsoy_1998, title={Maintenance Management Problems in a Semiconductor Wafer Fabrication Facility}, author={Uzsoy, R.}, year={1998}, month={Nov} }
 @article{mosley_teyner_uzsoy_1998, title={Maintenance scheduling and staffing policies in a wafer fabrication facility}, volume={11}, ISSN={0894-6507}, url={http://dx.doi.org/10.1109/66.670182}, DOI={10.1109/66.670182}, abstractNote={We examine how to reduce the adverse effects of machine down time by prioritizing production equipment for attention by a limited number of maintenance personnel. The maintenance scheduling policies use system information to determine which machines are the most critical at a given time. This information includes repair times, queue lengths, due dates, available capacity, and steady-state utilizations. The effects of different staffing levels are also considered. A discrete-event simulation model of a wafer fabrication facility is used to examine the performance of the different policies. Results indicate that the choice of maintenance scheduling policy can significantly affect system performance under restrictive staffing-levels. Moreover, factory performance is shown to be sensitive to small changes in staffing level.}, number={2}, journal={IEEE Transactions on Semiconductor Manufacturing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Mosley, S.A. and Teyner, T. and Uzsoy, R.M.}, year={1998}, month={May}, pages={316–323} }
 @misc{teyner_uzsoy_1998, title={Management of Spare Parts Inventories in a Wafer Fabrication Facility}, author={Teyner, T. and Uzsoy, R.}, year={1998}, month={May} }
 @article{mehta_uzsoy_1998, title={Minimizing total tardiness on a batch processing machine with incompatible job families}, volume={30}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408179808966448}, DOI={10.1080/07408179808966448}, abstractNote={Motivated by an application in semiconductor manufacturing, we study the problem of minimizing total tardiness on a batch processing machine with incompatibl8e job families, where all jobs of the same family have identical processing times and jobs of different families cannot be processed together. We present a dynamic programming algorithm which has polynomial time complexity when the number of job families and the batch machine capacity are fixed. We also examine various heuristic solution procedures which can provide near optimal solutions in a reasonable amount of computation time.}, number={2}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Mehta, Sanjay V. and Uzsoy, Reha}, year={1998}, month={Feb}, pages={165–178} }
 @misc{uzsoy_mehta_1998, title={Predictable Scheduling of Job Shops Subject To Machine Breakdowns}, author={Uzsoy, R. and Mehta, S.V.}, year={1998}, month={Mar} }
 @inproceedings{o’donovan_mckay_uzsoy_1998, title={Predictable Scheduling of a Single Machine with Breakdowns and Sensitive Jobs}, author={O’Donovan, R. and McKay, K.N. and Uzsoy, R.}, year={1998}, month={Apr} }
 @article{mehta_uzsoy_1998, title={Predictable scheduling of a job shop subject to breakdowns}, volume={14}, ISSN={1042-296X}, url={http://dx.doi.org/10.1109/70.678447}, DOI={10.1109/70.678447}, abstractNote={Schedule modification may delay or render infeasible the execution of external activities planned on the basis of the predictive schedule. Thus it is of interest to develop predictive schedules which can absorb disruptions without affecting planned external activities, while maintaining high shop performance. We present a predictable scheduling approach where the predictive schedule is built with such objectives. The procedure inserts additional idle time into the schedule to absorb the impacts of breakdowns. The amount and location of the additional idle time is determined from the breakdown and repair distributions as well as the structure of the predictive schedule. The effects of disruptions on planned support activities are measured by the deviations of job completion times in the realized schedule from those in the predictive schedule. We apply our approach to minimizing maximum lateness in a job shop environment with random machine breakdowns, and show that it provides high predictability with minor sacrifices in shop performance.}, number={3}, journal={IEEE Transactions on Robotics and Automation}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Mehta, S.V. and Uzsoy, R.M.}, year={1998}, month={Jun}, pages={365–378} }
 @article{kempf_uzsoy_wang_1998, title={Scheduling a single batch processing machine with secondary resource constraints}, volume={17}, ISSN={0278-6125}, url={http://dx.doi.org/10.1016/s0278-6125(98)80008-3}, DOI={10.1016/s0278-6125(98)80008-3}, abstractNote={This paper studies the problems of minimizing total completion time (ΣCi) and makespan (Cmax) on a single batch processing machine with job families and secondary resource constraints. The motivation for this problem is the burn-in operation in the final testing stage of semiconductor manufacturing, where both oven capacity and the number of boards available may constrain scheduling decisions. Because both problems are NP-hard, integer programming formulations are developed for special cases and are then used to develop heuristics. Extensive computational experiments show that the heuristics are capable of consistently obtaining good solutions in modest CPU times.}, number={1}, journal={Journal of Manufacturing Systems}, publisher={Elsevier BV}, author={Kempf, Karl G. and Uzsoy, Reha and Wang, Cheng-Shuo}, year={1998}, month={Jan}, pages={37–51} }
 @article{uzsoy_venkatachalam_1998, title={Supply Chain Management for Companies with Product Recovery and Remanufacturing Capability}, volume={7}, journal={International Journal of Environmentally Conscious Design and Manufacturing}, author={Uzsoy, R. and Venkatachalam, G.}, year={1998}, pages={59–72} }
 @article{demirkol_mehta_uzsoy_1997, title={A Computational Study of Shifting Bottleneck Procedures for Shop Scheduling Problems}, volume={3}, ISSN={1381-1231}, url={http://dx.doi.org/10.1023/a:1009627429878}, DOI={10.1023/a:1009627429878}, number={2}, journal={Journal of Heuristics}, publisher={Springer Science and Business Media LLC}, author={Demirkol, Ebru and Mehta, Sanjay and Uzsoy, Reha}, year={1997}, month={Nov}, pages={111–137} }
 @article{geiger_kempf_uzsoy_1997, title={A Tabu search approach to scheduling an automated wet etch station}, volume={16}, ISSN={0278-6125}, url={http://dx.doi.org/10.1016/s0278-6125(97)85674-9}, DOI={10.1016/s0278-6125(97)85674-9}, abstractNote={This paper addresses a production scheduling problem arising at the wet etching process in a semiconductor wafer fabrication facility. Material handling capacity, material processing constraints, and mixed storage policies are considered in formulating the problem as a flow shop sequencing problem with the objective of minimizing makespan (Cmax). Efficient heuristics and a tabu search procedure are developed to generate high-quality solutions in reasonable computational time. Extensive computational experiments evaluating the performance of the heuristics are reported.}, number={2}, journal={Journal of Manufacturing Systems}, publisher={Elsevier BV}, author={Geiger, Christopher D. and Kempf, Karl G. and Uzsoy, Reha}, year={1997}, month={Jan}, pages={102–116} }
 @article{geiger_hase_takoudis_uzsoy_1997, title={Alternative facility layouts for semiconductor wafer fabrication facilities}, volume={20}, ISSN={1083-4400}, url={http://dx.doi.org/10.1109/3476.622885}, DOI={10.1109/3476.622885}, abstractNote={Semiconductor wafer fabrication facilities are widely acknowledged to be among the most complicated industrial systems from a production planning and control point of view. The design of most wafer fabrication facilities has followed the process layout, where similar machines are located together. This feeds to complex, reentrant product flows through the facility. In this paper, we examine the effects on fab cycle time of a number of alternative layouts or machine dedication policies using a process for manufacturing three-dimensional (3-D) complementary metal-oxide-semiconductor (CMOS) devices as a research vehicle. We examine the performance of the layouts under different levels of machine breakdown, utilization, transfer time between stations, and setup times. Results show that cellular layouts, where machines are dedicated to a limited number of process steps, require more machinery but perform well when setup and transfer times are high and machinery is reliable. As machines become more unreliable, the flexibility of the process layouts becomes a major advantage. An interesting result is that the addition of modest amounts of extra capacity at critical workstations can significantly improve the cycle time performance of a fab.}, number={2}, journal={IEEE Transactions on Components, Packaging, and Manufacturing Technology: Part C}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Geiger, C.D. and Hase, R. and Takoudis, C.G. and Uzsoy, R.}, year={1997}, month={Apr}, pages={152–163} }
 @inproceedings{demirkol_uzsoy_1997, title={Decomposition Methods for Scheduling Complex Job Shops}, author={Demirkol, E. and Uzsoy, R.}, year={1997}, month={Oct} }
 @inproceedings{uzsoy_wang_1997, place={Austin, TX}, title={Decomposition procedures for global scheduling of complex job shops}, url={http://dx.doi.org/10.1109/iemt.1997.626955}, DOI={10.1109/iemt.1997.626955}, abstractNote={We describe a prototype decomposition procedure which uses global information on shop status to develop improved schedules for wafer fabrication facilities. The system studied contains reentrant product flows, multiple products and both unit capacity and batch machines. Preliminary experiments show that the decomposition procedure yields significantly better schedules in reasonable CPU times.}, booktitle={Twenty First IEEE/CPMT International Electronics Manufacturing Technology Symposium Proceedings 1997 IEMT Symposium}, publisher={IEEE}, author={Uzsoy, R. and Wang, Cheng-Shuo}, year={1997} }
 @misc{uzsoy_1997, title={Disassembly Configurations and Supply Chain Management for Companies with Product Recovery and Remanufacturing}, author={Uzsoy, R.}, year={1997}, month={Sep} }
 @misc{teyner_uzsoy_1997, title={Dispatching and Maintenance Management in a Wafer Fab Operating Under Theory of Constraints}, author={Teyner, T. and Uzsoy, R.}, year={1997}, month={Jan} }
 @article{kayton_teyner_schwartz_uzsoy_1997, title={Focusing Maintenance Improvement Efforts in a Wafer Fabrication Facility Operating Under Theory of Constraints}, number={Fourth Quarter}, journal={Production and Inventory Management}, author={Kayton, D. and Teyner, T. and Schwartz, C. and Uzsoy, R.}, year={1997}, pages={51–57} }
 @article{uzsoy_yang_1997, title={MINIMIZING TOTAL WEIGHTED COMPLETION TIME ON A SINGLE BATCH PROCESSING MACHINE}, volume={6}, ISSN={1059-1478}, url={http://dx.doi.org/10.1111/j.1937-5956.1997.tb00415.x}, DOI={10.1111/j.1937-5956.1997.tb00415.x}, abstractNote={ We study the problem of scheduling jobs on a single batch processing machine to minimize the total weighted completion time. A batch processing machine is one that can process a number of jobs simultaneously as a batch. The processing time of a batch is given by the processing time of the longest job in the batch. We present a branch and bound algorithm to obtain optimal solutions and develop lower bounds and dominance conditions. We also develop a number of heuristics and evaluate their performance through extensive computational experiments. Results show that two of the heuristics consistently generate high‐quality solutions in modest CPU times. }, number={1}, journal={Production and Operations Management}, publisher={Wiley}, author={Uzsoy, Reha and Yang, Yaoyu}, year={1997}, pages={57–73} }
 @inproceedings{demirkol_uzsoy_1997, title={Performance of Decomposition Methods for Complex Workshops Under Multiple Criteria}, booktitle={Proceedings of the 21st International Conference on Computers and Industrial Engineering}, author={Demirkol, E. and Uzsoy, R.}, year={1997}, month={Mar} }
 @inbook{uzsoy_1997, place={New York}, edition={8}, title={Production Engineering}, booktitle={McGraw-Hill Encyclopedia of Science and Technology}, publisher={McGraw-Hill}, author={Uzsoy, R.}, year={1997} }
 @inproceedings{uzsoy_1997, place={San Francisco, CA}, title={Production planning for companies with product recovery and remanufacturing capability}, url={http://dx.doi.org/10.1109/isee.1997.605342}, DOI={10.1109/isee.1997.605342}, abstractNote={We present an integrated set of models addressing issues of production planning in supply chains involving product recovery and disassembly. The supply chain models can be used to develop production plans in the short term, or examine the effects of different strategies in the long term. Uncertainty is addressed by using deterministic models to solve a range of different scenarios. We also develop models to determine profitable disassembly configurations for single and multiple products. Results to date are reported and future directions discussed.}, booktitle={Proceedings of the 1997 IEEE International Symposium on Electronics and the Environment. ISEE-1997}, publisher={IEEE}, author={Uzsoy, R.}, year={1997} }
 @article{tamer unal_uzsoy_kiran_1997, title={Rescheduling on a Single Machine with Part Type Dependent Setup Times and Due Dates}, volume={70}, ISSN={0254-5330}, url={http://dx.doi.org/10.1023/a:1018955111939}, DOI={10.1023/a:1018955111939}, journal={Annals of Operations Research}, publisher={Springer Science and Business Media LLC}, author={Tamer Unal, Ali and Uzsoy, Reha and Kiran, Ali S.}, year={1997}, pages={93–113} }
 @article{chand_traub_uzsoy_1997, title={Rolling horizon procedures for the single machine deterministic total completion time scheduling problem with release dates}, volume={70}, ISSN={0254-5330}, url={http://dx.doi.org/10.1023/a:1018961818782}, DOI={10.1023/a:1018961818782}, journal={Annals of Operations Research}, publisher={Springer Science and Business Media LLC}, author={Chand, Suresh and Traub, Rodney and Uzsoy, Reha}, year={1997}, month={Apr}, pages={115–125} }
 @inproceedings{akcali_hamlin_teyner_uzsoy_venkatachalam_1997, place={San Francisco, CA}, title={Spare parts inventory management for semiconductor wafer fabrication facilities}, url={http://dx.doi.org/10.1109/issm.1997.664484}, DOI={10.1109/issm.1997.664484}, abstractNote={We consider the problem of managing spare parts inventories in a semiconductor wafer fabrication facility. We study the performance of four different inventory control policies using simulation and mathematical models. Preliminary results show that two of the models yield significant improvements over the current inventory management policy.}, booktitle={1997 IEEE International Symposium on Semiconductor Manufacturing Conference Proceedings (Cat. No.97CH36023)}, publisher={IEEE}, author={Akcali, E. and Hamlin, R.D. and Teyner, T. and Uzsoy, R. and Venkatachalam, G.}, year={1997} }
 @misc{uzsoy_1997, title={Supply Chain Management in Electronics Manufacturing with Remanufacturing Capability}, author={Uzsoy, R.}, year={1997}, month={Nov} }
 @article{chand_traub_uzsoy_1996, title={An iterative heuristic for the single machine dynamic total completion time scheduling problem}, volume={23}, ISSN={0305-0548}, url={http://dx.doi.org/10.1016/0305-0548(95)00071-2}, DOI={10.1016/0305-0548(95)00071-2}, abstractNote={We address the problem of scheduling a single machine to minimize the total completion time in the face of dynamic job arrivals. Since the problem is strongly NP-hard, considerable research has been devoted to examining one-pass heuristic procedures for this problem. In this paper we present an iterative improvement heuristic which operates by modifying the problem data in a manner that allows one-pass heuristics to generate improved solutions. Computational experiments show that the procedure obtains significant improvements over a variety of one-pass heuristics in modest CPU times.}, number={7}, journal={Computers & Operations Research}, publisher={Elsevier BV}, author={Chand, Suresh and Traub, Rodney and Uzsoy, Reha}, year={1996}, month={Jul}, pages={641–651} }
 @misc{uzsoy_1996, title={Decomposition Methods for Scheduling Complex Job Shops}, author={Uzsoy, R.}, year={1996}, month={Oct} }
 @article{ovacik_uzsoy_1996, title={Decomposition methods for scheduling semiconductor testing facilities}, volume={8}, ISSN={0920-6299 1572-9370}, url={http://dx.doi.org/10.1007/bf00170018}, DOI={10.1007/bf00170018}, number={4}, journal={International Journal of Flexible Manufacturing Systems}, publisher={Springer Science and Business Media LLC}, author={Ovacik, IrfanM. and Uzsoy, Reha}, year={1996}, month={Oct} }
 @inproceedings{uzsoy_venkatadri_1996, title={Determining Disassembly Configurations in Remanufacturing}, author={Uzsoy, R. and Venkatadri, U.}, year={1996}, month={May} }
 @inproceedings{kayton_teyner_schwartz_uzsoy_1996, place={Austin, TX}, title={Effects of dispatching and down time on the performance of wafer fabs operating under theory of constraints}, url={http://dx.doi.org/10.1109/iemt.1996.559681}, DOI={10.1109/iemt.1996.559681}, abstractNote={A number of companies have reported significant improvements in manufacturing performance through implementing the concepts of the Theory of Constraints suggested by Goldratt (1986). However, the implementation of these concepts in wafer fabs is not straightforward due to the presence of reentrant product flows. In this paper we examine the effects of downtime at non-bottleneck machines and different dispatching rules on the performance of a wafer fab operating under the Drum-Buffer-Rope release policy (Goldratt and Fox 1986). Our results show that downtime at non-bottleneck machines has significant detrimental effects on fab performance, and that the Critical Ratio dispatching rule performs well in terms of the tradeoff between cycle time and throughput.}, booktitle={Nineteenth IEEE/CPMT International Electronics Manufacturing Technology Symposium}, publisher={IEEE}, author={Kayton, D. and Teyner, T. and Schwartz, C. and Uzsoy, R.}, year={1996} }
 @misc{uzsoy_1996, title={Global Scheduling Procedures for Semiconductor Manufacturing Facilities}, author={Uzsoy, R.}, year={1996}, month={Jul} }
 @inproceedings{uzsoy_rajagopalan_ovacik_1996, title={Integrating Optimum Estimation with Simulated Annealing for a Single Machine Scheduling Problem}, author={Uzsoy, R. and Rajagopalan, S. and Ovacik, I.M.}, year={1996}, month={May} }
 @article{holtsclaw_uzsoy_1996, title={Machine Criticality Measures and Subproblem Solution Procedures in Shifting Bottleneck Methods: A Computational Study}, volume={47}, ISSN={0160-5682}, url={http://dx.doi.org/10.2307/3010017}, DOI={10.2307/3010017}, number={5}, journal={The Journal of the Operational Research Society}, publisher={JSTOR}, author={Holtsclaw, Harry H. and Uzsoy, Reha}, year={1996}, month={May}, pages={666} }
 @inproceedings{lee_uzsoy_1996, title={Minimizing Makespan for Scheduling Semiconductor Burn-In Operations with Different Arrival Times}, author={Lee, C.Y. and Uzsoy, R.}, year={1996}, month={May} }
 @inproceedings{uzsoy_venkatachalam_1996, title={Production Planning with Product Recovery and Remanufacturing}, author={Uzsoy, R. and Venkatachalam, G.}, year={1996}, month={Oct} }
 @inproceedings{nemoto_akcali_uzsoy_1996, place={Austin, TX}, title={Quantifying the benefits of cycle time reduction in semiconductor wafer fabrication}, url={http://dx.doi.org/10.1109/iemt.1996.559705}, DOI={10.1109/iemt.1996.559705}, abstractNote={In recent years, semiconductor manufacturing has become extremely complex due to device size reduction. Hence the manufacturing cycle time, also called turn around time (TAT), which is defined as the time required from wafer input through probing test, becomes longer year by year. This renders the delay between process defect occurrence and detection a significant problem. On the other hand, customer demands for faster delivery are increasing because their product life cycles are getting shorter. Therefore, TAT reduction is important for semiconductor manufacturers not only to satisfy customer requirements, but also to remain competitive in their market. This paper examines the financial benefits of TAT reduction using stochastic simulation.}, booktitle={Nineteenth IEEE/CPMT International Electronics Manufacturing Technology Symposium}, publisher={IEEE}, author={Nemoto, K. and Akcali, E. and Uzsoy, R.}, year={1996}, pages={130–136} }
 @inproceedings{uzsoy_wang_1996, title={Scheduling Semiconductor Burn-In Operations in the Presence of Resource Constraints}, author={Uzsoy, R. and Wang, C.S.}, year={1996}, month={Oct} }
 @misc{uzsoy_1996, title={Shop Floor Control for Semiconductor Manufacturing Facilities}, author={Uzsoy, R.}, year={1996}, month={Oct} }
 @misc{uzsoy_1996, title={Shop Floor Control for Semiconductor Manufacturing Facilities}, author={Uzsoy, R.}, year={1996}, month={Apr} }
 @misc{uzsoy_1996, title={Shop Floor Control for Semiconductor Manufacturing Facilities}, author={Uzsoy, R.}, year={1996}, month={Mar} }
 @misc{uzsoy_1996, title={Shop Floor Control for Semiconductor Manufacturing Facilities}, author={Uzsoy, R.}, year={1996}, month={Jan} }
 @article{chand_traub_uzsoy_1996, title={Single-machine scheduling with dynamic arrivals: Decomposition results and an improved algorithm}, volume={43}, ISSN={0894-069X 1520-6750}, url={http://dx.doi.org/10.1002/(sici)1520-6750(199608)43:5<709::aid-nav7>3.0.co;2-9}, DOI={10.1002/(sici)1520-6750(199608)43:5<709::aid-nav7>3.0.co;2-9}, abstractNote={This article considers the single-machine dynamic scheduling problem where the jobs have different arrival times and the objective is to minimize the sum of completion times. This problem is known to be strongly NP-hard. We develop decomposition results for this problem such that a large problem can be solved by combining optimal solutions for several smaller problems. The decomposition results can be used with any implicit enumeration method to develop an optimal algorithm. Our computational experiment indicates that the computational efficiency of the currently best available branch-and-bound algorithm can be improved with the use of our decomposition results. © 1996 John Wiley & Sons, Inc.}, number={5}, journal={Naval Research Logistics}, publisher={Wiley}, author={Chand, Suresh and Traub, Rodney and Uzsoy, Reha}, year={1996}, month={Aug}, pages={709–719} }
 @inproceedings{uzsoy_clegg_williams_venkatadri_venkatachalam_1996, title={Supply Chain Coordination in the Presence of Remanufacturing}, author={Uzsoy, R. and Clegg, A. and Williams, D.J. and Venkatadri, U. and Venkatachalam, G.}, year={1996}, month={May} }
 @inproceedings{chen_takoudis_uzsoy_1996, place={Austin, TX}, title={Yield of silicon selective epitaxial growth and its role in the production planning and control of three-dimensional semiconductor devices}, url={http://dx.doi.org/10.1109/iemt.1996.559732}, DOI={10.1109/iemt.1996.559732}, abstractNote={We focus on the yield (Y) and growth rate (G) of silicon selective epitaxial growth (SEG) at 820 to 970/spl deg/C, and pressures between 40 and 150 Torr. Since the yield of silicon SEG is a potential bottleneck in the manufacture of three-dimensional integrated circuits, e.g., 3-D CMOS, basic knowledge of Y and its dependence on operating conditions, substrate surface parameters, and processing time is of key importance. The conditions investigated include deposition temperature, deposition pressure, SEG thickness, processing time, seed window area, distance between seed windows (local seed window density), and feed composition. The yield is found to improve with higher deposition temperatures, higher HCl feed flows, shorter processing times, higher Cl/H feed ratios, and lower Si/Cl feed ratios. The seed window area and distance between seed windows do not appear to affect the yield at the conditions studied. Growth rate uniformity is observed to improve with lower pressure and temperature, longer processing times, lower HCl feed concentrations, higher Si/Cl feed ratios, and lower Cl/H feed ratios. The implications of these observations for production planning and control of such facilities are discussed.}, booktitle={Nineteenth IEEE/CPMT International Electronics Manufacturing Technology Symposium}, publisher={IEEE}, author={Chen, S. and Takoudis, C. and Uzsoy, R.}, year={1996} }
 @inproceedings{demirkol_mehta_uzsoy_1995, title={A Computational Comparison of Shifting Bottleneck Procedures}, author={Demirkol, E. and Mehta, S.V. and Uzsoy, R.}, year={1995}, month={Dec} }
 @inproceedings{demirkol_mehta_uzsoy_1995, title={A Computational Comparison of Shifting Bottleneck Procedures}, author={Demirkol, E. and Mehta, S.V. and Uzsoy, R.}, year={1995}, month={Oct} }
 @inproceedings{geiger_kempf_uzsoy_1995, title={A Tabu Search Approach to Scheduling Automated Wet Etch Stations}, author={Geiger, C.D. and Kempf, K. and Uzsoy, R.}, year={1995}, month={Oct} }
 @inproceedings{chen_hase_takoudis_uzsoy_1995, title={Alternative Layouts for Semiconductor Wafer Fabrication Facilities}, booktitle={Proceedings of the NSF Grantees Conference}, author={Chen, S. and Hase, R. and Takoudis, C.G. and Uzsoy, R.}, year={1995}, month={Jan} }
 @inproceedings{hase_uzsoy_takoudis_1995, place={Austin, TX}, title={Alternative facility layouts for semiconductor wafer fabrication facilities}, url={http://dx.doi.org/10.1109/iemt.1995.526191}, DOI={10.1109/iemt.1995.526191}, abstractNote={Examines the performance of several different cellular and functional layouts using simulation models of the different facility designs. The performance measure of interest is the mean time in system or cycle time of lots. Our results show that the presence of unreliable machinery causes the performance of cellular layouts to deteriorate, while the presence of significant setup times improves their performance relative to other layouts. The results also indicate that a very modest amount of additional capacity at critical workcenters results in significant improvements in the performance of functional layouts.}, booktitle={Seventeenth IEEE/CPMT International Electronics Manufacturing Technology Symposium. 'Manufacturing Technologies - Present and Future'}, publisher={IEEE}, author={Hase, R. and Uzsoy, R. and Takoudis, C.G.}, year={1995} }
 @inproceedings{chand_traub_uzsoy_1995, title={An Iterative Heuristic for Single Machine Dynamic Total Completion Time Problems}, author={Chand, S. and Traub, R. and Uzsoy, R.}, year={1995}, month={Oct} }
 @inproceedings{gary_kempf_smith_uzsoy_1995, title={Assessing the Quality of Production Schedules}, booktitle={Intelligent Scheduling Systems}, publisher={Kluwer Academic Publishing}, author={Gary, K. and Kempf, K. and Smith, S. and Uzsoy, R.}, editor={Scherer, W. and Brown, D.Editors}, year={1995}, month={Nov}, pages={148–164} }
 @book{moodie_uzsoy_yih_1995, title={Cellular Manufacturing: A Systems Engineering Approach}, publisher={Taylor and Francis}, year={1995} }
 @inproceedings{ovacik_uzsoy_1995, title={Decomposition Algorithms for Scheduling Complex Job Shops}, booktitle={Proceedings of the NSF Grantees Conference}, author={Ovacik, I.M. and Uzsoy, R.}, year={1995}, month={Jan} }
 @misc{ovacik_uzsoy_1995, title={Decomposition Algorithms for Scheduling Complex Job Shops}, author={Ovacik, I.M. and Uzsoy, R.}, year={1995}, month={Jul} }
 @inproceedings{ovacik_uzsoy_1995, title={Decomposition Methods for Scheduling Large Complex Shops}, booktitle={Proceedings of the Fourth Industrial Engineering Research Conference}, author={Ovacik, I.M. and Uzsoy, R.}, year={1995}, month={May} }
 @inproceedings{uzsoy_ovacik_1995, title={Decomposition Methods for Scheduling Problems}, author={Uzsoy, R. and Ovacik, I.M.}, year={1995}, month={Oct} }
 @inproceedings{demirkol_uzsoy_ovacik_1995, place={Austin, TX}, title={Decomposition algorithms for scheduling semiconductor testing facilities}, url={http://dx.doi.org/10.1109/iemt.1995.526115}, DOI={10.1109/iemt.1995.526115}, abstractNote={The research described in this paper began in 1988 and is directed at developing effective computerized scheduling procedures for a semiconductor testing facility. To this end we first give a brief overview of the testing process and management goals. We then discuss the performance of a series of different scheduling techniques for this problem, beginning with local dispatching rules that use very limited information through more complex dispatching procedures incorporating local optimization and look-ahead capabilities, culminating in a series of decomposition procedures that take a global view of the test area while making scheduling decisions. Our computational experiments indicate that exploiting the real-time factory status information available in existing factory automation systems can result in significant improvements in shop performance. We conclude the paper with a summary and a discussion of future research directions.}, booktitle={Seventeenth IEEE/CPMT International Electronics Manufacturing Technology Symposium. 'Manufacturing Technologies - Present and Future'}, publisher={IEEE}, author={Demirkol, E. and Uzsoy, R. and Ovacik, I.M.}, year={1995} }
 @inproceedings{traub_chand_uzsoy_1995, title={Identification of Forecast Horizons in Single Machine Dynamic Scheduling Problems}, author={Traub, R. and Chand, S. and Uzsoy, R.}, year={1995}, month={Oct} }
 @misc{gary_uzsoy_smith_kempf_1995, title={Measuring the Quality of Manufacturing Schedules}, ISBN={9781461359548 9781461522638}, url={http://dx.doi.org/10.1007/978-1-4615-2263-8_6}, DOI={10.1007/978-1-4615-2263-8_6}, journal={Intelligent Scheduling Systems}, publisher={Springer US}, author={Gary, Kevin and Uzsoy, Reha and Smith, Stephen P. and Kempf, Karl}, year={1995}, pages={129–154} }
 @misc{uzsoy_1995, title={OR/MS Career Opportunities in Engineering Schools}, author={Uzsoy, R.}, year={1995}, month={Oct} }
 @inproceedings{mehta_uzsoy_1995, title={Predictable Scheduling to Reduce the Effects of Disruptions on Production Schedules}, author={Mehta, S.V. and Uzsoy, R.}, year={1995}, month={Oct} }
 @inproceedings{mehta_uzsoy_1995, title={Predictable Scheduling: An Approach to Reducing the Effects of Uncertainties on Production Schedules}, booktitle={Proceedings of the Fourth Industrial Engineering Research Conference}, author={Mehta, S.V. and Uzsoy, R.}, year={1995}, month={May} }
 @inproceedings{clegg_williams_uzsoy_1995, place={Orlando, FL}, title={Production planning for companies with remanufacturing capability}, url={http://dx.doi.org/10.1109/isee.1995.514973}, DOI={10.1109/isee.1995.514973}, abstractNote={While much work is in progress on developing environmentally benign products and processes, there has been little work to date on how recycling and remanufacturing may affect companies' operations management policies. In this paper we present linear programming models of production systems with remanufacturing capability. The models can be used to examine the effects of different cost structures on the long-term viability of remanufacturing operations,as well as short-term operations management issues. Work is in progress on applying these models to a telephone remanufacturing operation.}, booktitle={Proceedings of the 1995 IEEE International Symposium on Electronics and the Environment ISEE (Cat. No.95CH35718)}, publisher={IEEE}, author={Clegg, A.J. and Williams, D.J. and Uzsoy, R.}, year={1995} }
 @misc{chen_hase_mordaunt_uzsoy_takoudis_1995, title={Relationships between process fundamentals, facility design, and production control of semiconductor manufacturing systems}, ISSN={0277-786X}, url={http://dx.doi.org/10.1117/12.221317}, DOI={10.1117/12.221317}, abstractNote={Basic interrelationships among yields, processing environments, and shop-floor scheduling in semiconductor wafer fabrication facilities are currently under study. In this paper, we focus on a hypothetical wafer fabrication facility producing 3D CMOS devices designed and developed at Purdue. A key step of this sequence of this process is silicon selective epitaxial growth (SEG). Our emphasis is on the effects of substrate temperature, and system pressure on the quality of the films grown through silicon SEG. Such studies result in relationships between yield and processing conditions. For example, higher substrate temperatures, in the range of 800 to 1000 degree(s)C studied, appear to result in significantly lower defect densities for all sizes of seed windows investigated. Our experimental observations on relationships between yield and time can in turn can be used to examine the viability of different layouts for wafer fabrication facilities. We focus on cellular layouts, where machines are organized into cells, each dedicated to the processing of a certain subset of operations. For the 3D CMOS fab mentioned previously, we present results of simulation experiments that indicate that under certain conditions, cellular layouts result in better cycle time performance at the expense of some additional capital investment.}, journal={SPIE Proceedings}, publisher={SPIE}, author={Chen, Shannon and Hase, Rieko C. and Mordaunt, Kaine and Uzsoy, Reha M. and Takoudis, Christos G.}, editor={Sabnis, Anant G. and Raaijmakers, Ivo J.Editors}, year={1995}, month={Sep} }
 @inproceedings{mehta_uzsoy_1995, title={Robust Predictive Schedules for a Single Machine}, author={Mehta, S.V. and Uzsoy, R.}, year={1995}, month={Jun} }
 @article{ovacik_uzsoy_1995, title={Rolling horizon procedures for dynamic parallel machine scheduling with sequence-dependent setup times}, volume={33}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207549508904867}, DOI={10.1080/00207549508904867}, abstractNote={SUMMARY We present a family of rolling horizon heuristics for minimizing maximum lateness on parallel identical machines in the presence of sequence dependent setup times and dynamic job arrivals. This problem arises as a subproblem in a decomposition procedure for more complex job shop scheduling problems. The procedures solve a series of single machine subproblems to optimality and implement only part of the solution. Extensive computational experiments show that these methods significantly outperform dispatching rules combined with local search methods, both on average and in the worst case. Their performance advantage is particularly pronounced when there is high competition for machine capacity.}, number={11}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Ovacik, I. M. and Uzsoy, R.}, year={1995}, month={Nov}, pages={3173–3192} }
 @article{ashby_uzsoy_1995, title={Scheduling and order release in a single-stage production system}, volume={14}, ISSN={0278-6125}, url={http://dx.doi.org/10.1016/0278-6125(95)98881-6}, DOI={10.1016/0278-6125(95)98881-6}, abstractNote={We develop a set of scheduling heuristics that integrate order release, group scheduling, and order sequencing for a make-to-order manufacturing facility organized into group technology cells. The procedures take into account both order due dates and sequence-dependent setup times. Simulation experiments are used to compare the performance of the procedures to current practice. Results show that the new scheduling policies, which consider setup times as well as due dates in both order release and job sequencing decisions, substantially improve due date performance and show that both order release policies and dispatching rules have significant effects on system performance.}, number={4}, journal={Journal of Manufacturing Systems}, publisher={Elsevier BV}, author={Ashby, James R. and Uzsoy, Reha}, year={1995}, month={Jan}, pages={290–306} }
 @article{uzsoy_1995, title={Scheduling batch processing machines with incompatible job families}, volume={33}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207549508904839}, DOI={10.1080/00207549508904839}, abstractNote={The problem of scheduling a single batch processing machine with incompatible job families was studied, where jobs of different families cannot be processed together in the same batch. First static problems where all jobs are available simultaneously were considered and showed that for a regular performance measure there will be no unnecessary partial batches. This allowed us to develop efficient optimal algorithms to minimize makespan (Cmax), maximum lateness (Lmax) and total weighted completion time and apply some of these results to problems with parallel identical batch processing machines. Then problems withdynamic job arrivals were considered and an efficient optimal algorithm for minimizing Cmax and several heuristics to minimize Lmax were provided. Computational experiments showed that the heuristics developed for the latter problem consistently improve on dispatching solutions in very reasonable CPU times.}, number={10}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Uzsoy, R.}, year={1995}, month={Oct}, pages={2685–2708} }
 @inproceedings{toktay_uzsoy_1994, title={A Capacity Allocation Problem with Integer Side Constraints}, author={Toktay, L.B. and Uzsoy, R.}, year={1994}, month={Apr} }
 @inproceedings{mehta_uzsoy_1994, title={A Heuristic for Generating Robust Predictive Schedules}, author={Mehta, S.V. and Uzsoy, R.}, year={1994}, month={Apr} }
 @article{uzsoy_lee_martin vega_1994, title={A REVIEW OF PRODUCTION PLANNING AND SCHEDULING MODELS IN THE SEMICONDUCTOR INDUSTRY PART II: SHOP-FLOOR CONTROL}, volume={26}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408179408966627}, DOI={10.1080/07408179408966627}, abstractNote={Abstract In the first part of this review [62] we described the characteristics of semiconductor manufacturing environments and reviewed research on system performance evaluation and production planning. In this paper we focus on shop-floor control problems. We classify research to date by the solution techniques used, and discuss the relative advantages and disadvantages of the various approaches. We discuss the relationship between shop-floor control and production planning and suggest future research directions.}, number={5}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Uzsoy, Reha and Lee, Chung Yee and Martin Vega, Louis A.}, year={1994}, month={Sep}, pages={44–55} }
 @article{ulusoy_uzsoy_1994, title={A robust strategy approach to a strategic mobility problem}, volume={79}, ISSN={0377-2217}, url={http://dx.doi.org/10.1016/0377-2217(94)90357-3}, DOI={10.1016/0377-2217(94)90357-3}, abstractNote={In this paper a particular strategic mobility problem, the strategic airlift problem, is investigated with the aims of bringing an interesting and challenging class of problems to the attention of the research community and suggesting a solution procedure as a starting point for future research. The proposed solution procedure has two levels. The first level addresses the decisions of locating aircraft and supplies over the bases. This is done by generating a set scenarios over a set possible demand patterns (fronts) in which each front is assigned a probability of occurrence. Origin-destination matrices for each front are based on the supply locations and are used to allocate aircraft over the bases. The second level consists of routing the supplies so as to minimize the maximum operation time over all aircraft. Several heuristic procedures are applied at each level. Over a particular range of occurrence probabilities a dominant strategy is sought by applying a robustness measure and a dominance criterion. The operation of the procedure is illustrated by an application.}, number={2}, journal={European Journal of Operational Research}, publisher={Elsevier BV}, author={Ulusoy, Gündüz and Uzsoy, Reha}, year={1994}, month={Dec}, pages={266–276} }
 @inproceedings{hase_takoudis_uzsoy_1994, title={Cellular and Reentrant Layouts for Wafer Fabrication}, booktitle={Proceedings of the Electrochemical Society Meeting}, author={Hase, R. and Takoudis, C.G. and Uzsoy, R.}, year={1994}, month={May} }
 @inproceedings{hase_takoudis_uzsoy_1994, title={Cellular and reentrant layouts for semiconductor wafer fabrication facilities}, url={http://dx.doi.org/10.1109/iemt.1994.404681}, DOI={10.1109/iemt.1994.404681}, abstractNote={We study alternative facility layouts for semiconductor wafer fabrication facilities using a process developed for manufacturing 3-dimensional CMOS devices as a research vehicle. Simulation experiments indicate that cellular layouts requiring only modestly higher capital investment can yield significantly lower cycle times in heavily loaded fabs. These results suggest that the savings in operating costs such as inventory holding cost over the life of the process may render the additional capital investment required by the cellular layouts economically justifiable.<<ETX>>}, booktitle={Proceedings of 16th IEEE/CPMT International Electronic Manufacturing Technology Symposium}, publisher={IEEE}, author={Hase, R. and Takoudis, C.G. and Uzsoy, R.}, year={1994}, pages={112–118,} }
 @inproceedings{ovacik_uzsoy_1994, title={Decomposition Algorithms for Scheduling Large Complex Job Shops}, author={Ovacik, I.M. and Uzsoy, R.}, year={1994}, month={Apr} }
 @misc{ovacik_uzsoy_1994, title={Decomposition Algorithms for Scheduling Large Complex Job Shops}, author={Ovacik, I.M. and Uzsoy, R.}, year={1994}, month={Oct} }
 @article{ovacik_uzsoy_1994, title={Exploiting shop floor status information to schedule complex job shops}, volume={13}, ISSN={0278-6125}, url={http://dx.doi.org/10.1016/0278-6125(94)90023-x}, DOI={10.1016/0278-6125(94)90023-x}, abstractNote={We propose a heuristic for scheduling complex job shops that uses the shop floor status information available in many of today's computerized systems to make dispatching decisions. We describe four variants of this procedure and evaluate their performance in three different shop configurations: a job shop with random routings, a reentrant flow shop, and a semiconductor testing facility. Results show that the algorithms perform better than dispatching rules with modest increases in computation time. The amount of improvement obtained depends on the shop configuration, with substantial improvements being obtained for the semiconductor testing facility and reentrant flow shops.}, number={2}, journal={Journal of Manufacturing Systems}, publisher={Elsevier BV}, author={Ovacik, Irfan M. and Uzsoy, Reha}, year={1994}, month={Jan}, pages={73–84} }
 @inproceedings{lee_martin-vega_uzsoy_hinchman_1994, title={Implementation of a Decision Support System for Scheduling Semiconductor Testing Operations}, author={Lee, C.Y. and Martin-Vega, L.A. and Uzsoy, R. and Hinchman, J.}, year={1994}, month={May} }
 @article{lee_lin_uzsoy_wong_1994, title={Implementation of a demand-pull system in a job shop environment}, volume={32}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207549408957108}, DOI={10.1080/00207549408957108}, abstractNote={Abstract This paper describes an implementation of JIT concepts in a medium-sized make-to-order manufacturing company. We develop a hybrid production control system for the company based on separating jobs with high production volumes following a standard routeing from relatively low-volume jobs with more complex routeings. The machines processing the high-volume standard-routeing jobs are treated as a virtual flow shop and controlled by a hybrid push/pull system, while the remainder of the floor is managed as a job shop. Initial tests have shown that this system can significantly improve throughput and simplify the production scheduling task. We believe that the system can be applied to a wide range of industries with similar characteristics. We also describe the testing of the system and the circumstances under which its implementation was discontinued, which indicate some of the difficulties faced by small manufacturers in implementing such systems.}, number={12}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Lee, C. Y. and Lin, C. S. and Uzsoy, R. and Wong, C. C.}, year={1994}, month={Dec}, pages={2915–2927} }
 @inproceedings{cetinkaya_uzsoy_1994, title={Lot Streaming in a Two-Stage Hybrid Flow Shop}, author={Cetinkaya, F.C. and Uzsoy, R.}, year={1994}, month={Apr} }
 @misc{uzsoy_takoudis_1994, title={Production Scheduling and Facility Design in Semiconductor Manufacturing}, author={Uzsoy, R. and Takoudis, C.G.}, year={1994}, month={Oct} }
 @misc{uzsoy_1994, title={Production Scheduling and Facility Design in Semiconductor Manufacturing}, author={Uzsoy, R.}, year={1994}, month={Mar} }
 @inproceedings{hase_burgos_chen_uzsoy_takoudis_1994, title={Relationships Between Process Fundamentals, Facility Design and Production Control of Semiconductor Manufacturing Systems}, booktitle={Proceedings of the 1994 Annual Meeting, American Institute of Chemical Engineers}, author={Hase, R.C. and Burgos, M.C. and Chen, S. and Uzsoy, R. and Takoudis, C.G.}, year={1994}, month={Nov} }
 @article{ovacikt_uzsoy_1994, title={Rolling horizon algorithms for a single-machine dynamic scheduling problem with sequence-dependent setup times}, volume={32}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207549408956998}, DOI={10.1080/00207549408956998}, abstractNote={We present a family of rolling horizon heuristics to minimize maximum lateness on a single machine in the presence of sequence-dependent setup times. This problem occurs as a subproblem in a decomposition procedure for more complicated job shop scheduling problems. The procedures solve a sequence of subproblems to optimality with a branch and bound algorithm and implements only part of the solution obtained. The size and number of the subproblems are controlled by algorithm parameters. Extensive computational experiments show that these procedures outperform myopic dispatching rules by an order of magnitude, both on average and in the worst case, in very reasonable computation times.}, number={6}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Ovacikt, I. M. and Uzsoy, R.}, year={1994}, month={Jun}, pages={1243–1263} }
 @inproceedings{ovacik_uzsoy_1994, title={Scheduling Algorithms for Parallel Machines with Sequence-Dependent Setup Times}, author={Ovacik, I.M. and Uzsoy, R.}, year={1994}, month={Apr} }
 @inproceedings{uzsoy_1994, title={Scheduling Complex Dynamic Job Shops with Application to Semiconductor Manufacturing}, booktitle={Proceedings of the NSF Grantees Conference}, author={Uzsoy, R.}, year={1994}, month={Jan}, pages={383–384} }
 @article{uzsoy_1994, title={Scheduling a single batch processing machine with non-identical job sizes}, volume={32}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207549408957026}, DOI={10.1080/00207549408957026}, abstractNote={The problem of scheduling jobs with non-identical capacity requirements or sizes on a single batch processing machine to minimize total completion time and makespan is studied. These problems are proven to be NP-hard and heuristics are developed for both, as well as a branch and bound algorithm for the total completion time problem. Computational experiments show that the heuristics are capable of rapidly obtaining near-optimal solutions.}, number={7}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Uzsoy, R.}, year={1994}, month={Jul}, pages={1615–1635} }
 @inproceedings{chand_uzsoy_traub_1994, title={Single Machine Dynamic Scheduling: Decomposition Results and Rolling Horizon Procedures}, author={Chand, S. and Uzsoy, R. and Traub, R.}, year={1994}, month={Apr} }
 @inproceedings{chand_traub_uzsoy_1994, title={Single Machine Scheduling with Dynamic Arrivals: Decomposition Results and a Forward Algorithm}, author={Chand, S. and Traub, R. and Uzsoy, R.}, year={1994}, month={May} }
 @misc{ovacik_uzsoy_1993, title={A Decomposition Approach for Scheduling Complex Dynamic Job Shops}, author={Ovacik, I.M. and Uzsoy, R.}, year={1993}, month={Dec} }
 @misc{ovacik_uzsoy_1993, title={A Decomposition Approach for Scheduling Complex Dynamic Job Shops}, author={Ovacik, I.M. and Uzsoy, R.}, year={1993}, month={Sep} }
 @misc{uzsoy_1993, title={A Decomposition Approach for Scheduling Semiconductor Testing Operations}, author={Uzsoy, R.}, year={1993}, month={Aug} }
 @misc{uzsoy_1993, title={A Shifting Bottleneck Algorithm for Scheduling Complex Dynamic Job Shops}, author={Uzsoy, R.}, year={1993}, month={Feb} }
 @inproceedings{kempf_ovacik_uzsoy_1993, title={Aggregation and Segmentation in Evaluation and Comparison of Production Schedules}, author={Kempf, K.G. and Ovacik, I.M. and Uzsoy, R.}, year={1993}, month={Nov} }
 @inproceedings{gary_uzsoy_kempf_smith_1993, title={Assessing the Quality of Production Schedules}, publisher={McGill University}, author={Gary, K. and Uzsoy, R. and Kempf, K. and Smith, S.}, year={1993}, month={Jun} }
 @inproceedings{uzsoy_1993, title={Decomposition Methods for Scheduling Complex Dynamic Job Shops}, booktitle={Proceedings of the NSF Grantees Conference}, author={Uzsoy, R.}, year={1993}, month={Jan}, pages={1253–1257} }
 @inproceedings{kempf_uzsoy_1993, title={Decomposition Methods for Scheduling Complex Job Shops}, author={Kempf, K.G. and Uzsoy, R.}, year={1993}, month={Nov} }
 @inproceedings{ovacik_uzsoy_1993, title={Exploiting Real-Time Shop Floor Status Information to Schedule Complex Job Shops}, booktitle={Proceedings of the Second Industrial Engineering Research Conference}, author={Ovacik, I.M. and Uzsoy, R.}, year={1993}, month={May}, pages={868–872} }
 @article{lee_martin vega_uzsoy_hinchman_1993, title={Implementation of a decision support system for scheduling semiconductor test operations}, volume={03}, ISSN={0960-3131}, url={http://dx.doi.org/10.1142/s0960313193000140}, DOI={10.1142/s0960313193000140}, abstractNote={The problem of scheduling semiconductor test operations is a dynamic job shop scheduling problem complicated by the presence of machines with different scheduling characteristics and sequence-dependent setup times. The well-known intractability of job shop scheduling problems and the need to address multiple, conflicting management goals motivates the use of a decision support system (DSS) combining scheduling heuristics and existing information systems to support the scheduling function. The DSS is currently in use in two separate testing facilities, where management feels it has significantly improved shop performance and reduced production planning workload.}, number={03}, journal={Journal of Electronics Manufacturing}, publisher={World Scientific Pub Co Pte Lt}, author={Lee, Chung Yee and Martin Vega, Louis A. and Uzsoy, Reha and Hinchman, Jim}, year={1993}, month={Sep}, pages={121–131} }
 @article{chandru_lee_uzsoy_1993, title={Minimizing total completion time on a batch processing machine with job families}, volume={13}, ISSN={0167-6377}, url={http://dx.doi.org/10.1016/0167-6377(93)90030-k}, DOI={10.1016/0167-6377(93)90030-k}, abstractNote={We consider the problem of minimizing the total completion time on a single batch processing machine. The set of jobs to be scheduled can be partitioned into a number of families, where all jobs in the same family have the same processing time. The machine can process at most B jobs simultaneously as a batch, and the processing time of a batch is equal to the processing time of the longest job in the batch. We analyze that properties of an optimal schedule and develop a dynamic programming algorithm of polynomial time complexity when the number of job families is fixed. The research is motivated by the problem of scheduling burn-in ovens in the semiconductor industry.}, number={2}, journal={Operations Research Letters}, publisher={Elsevier BV}, author={Chandru, Vijaya and Lee, Chung-Yee and Uzsoy, Reha}, year={1993}, month={Mar}, pages={61–65} }
 @article{chandru_lee_uzsoy_1993, title={Minimizing total completion time on batch processing machines}, volume={31}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/00207549308956847}, DOI={10.1080/00207549308956847}, abstractNote={We study the problem of minimizing total completion time on single and parallel batch processing machines. A batch processing machine is one which can process up to B jobs simultaneously. The processing time of a batch is equal to the largest processing time among all jobs in the batch. This problem is motivated by burn-in operations in the final testing stage of semiconductor manufacturing and is expected to occur in other production environments. We provide an exact solution procedure for the single-machine problem and heuristic algorithms for both single and parallel machine problems. While the exact algorithms have limited applicability due to high computational requirements, extensive experiments show that the heuristics are capable of consistently obtaining near-optimal solutions in very reasonable CPU times.}, number={9}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Chandru, V. and Lee, C. Y. and Uzsoy, R.}, year={1993}, month={Sep}, pages={2097–2121} }
 @article{uzsoy_church_ovacik_hinchman_1993, title={Performance evaluation of dispatching rules for semiconductor testing operations}, volume={03}, ISSN={0960-3131}, url={http://dx.doi.org/10.1142/s0960313193000115}, DOI={10.1142/s0960313193000115}, abstractNote={We evaluate the performance of several dispatching rules in a semiconductor testing environment and examine the effects of uncertainties in problem data and job arrival patterns. A series of simulation experiments shows that a single dispatching rule seldom performs well for several different performance measures simultaneously, non-homogenous job arrival patterns significantly affect several aspects of system performance while uncertainty in problem data does not, and the choice of dispatching rules for a given performance measure is robust to both arrival patterns and uncertainties.}, number={02}, journal={Journal of Electronics Manufacturing}, publisher={World Scientific Pub Co Pte Lt}, author={Uzsoy, Reha and Church, Laura K. and Ovacik, Irfan M. and Hinchman, Jim}, year={1993}, month={Jun}, pages={95–105} }
 @inproceedings{perry_uzsoy_1993, place={Santa Clara, CA}, title={Reactive scheduling of a semiconductor testing facility}, url={http://dx.doi.org/10.1109/iemt.1993.398156}, DOI={10.1109/iemt.1993.398156}, abstractNote={The authors describe an approach to scheduling complex job shops such as semiconductor testing operations which uses the global shop-floor information available from computerized Factory Control Systems. The approach combines a decomposition approach for the static problem with an EDR approach to handling the dynamic events in the system. Preliminary experiments show that these rescheduling policies have performance comparable to myopic dispatching rules, and the implementation of better subproblem solution methods in the decomposition should lead to substantial further improvements.<<ETX>>}, booktitle={Proceedings of 15th IEEE/CHMT International Electronic Manufacturing Technology Symposium}, publisher={IEEE}, author={Perry, C.N. and Uzsoy, R.}, year={1993} }
 @inproceedings{ovacik_uzsoy_1993, title={Rolling Horizon Algorithms for a Single-Machine Dynamic Scheduling Problem with Sequence-Dependent Setup Times}, author={Ovacik, I.M. and Uzsoy, R.}, year={1993}, month={Nov} }
 @inproceedings{chand_traub_uzsoy_1993, title={Rolling Horizon Algorithms for the Dynamic Total Completion Time Problem}, author={Chand, S. and Traub, R. and Uzsoy, R.}, year={1993}, month={May} }
 @misc{uzsoy_1993, title={Scheduling Batch Processing Machines with Nonidentical Job Sizes}, author={Uzsoy, R.}, year={1993}, month={Mar} }
 @article{ovacik_uzsoy_1993, title={Worst-case error bounds for parallel machine scheduling problems with bounded sequence-dependent setup times}, volume={14}, ISSN={0167-6377}, url={http://dx.doi.org/10.1016/0167-6377(93)90089-y}, DOI={10.1016/0167-6377(93)90089-y}, abstractNote={We consider minimizing makespan (Cmax) and maximum lateness (Lmax) on parallel identical machines with sequence-dependent setup times. We show that the optimal schedule need not be a list schedule. Motivated by a practical scheduling problem, we study the class of problems where setup times are bounded by processing times and develop tight worst case error bounds for list scheduling algorithms to minimize Cmax and Lmax.}, number={5}, journal={Operations Research Letters}, publisher={Elsevier BV}, author={Ovacik, Irfan M. and Uzsoy, Reha}, year={1993}, month={Dec}, pages={251–256} }
 @article{uzsoy_lee_martin vega_1992, title={A REVIEW OF PRODUCTION PLANNING AND SCHEDULING MODELS IN THE SEMICONDUCTOR INDUSTRY PART I: SYSTEM CHARACTERISTICS, PERFORMANCE EVALUATION AND PRODUCTION PLANNING}, volume={24}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408179208964233}, DOI={10.1080/07408179208964233}, abstractNote={Although the national importance of the semiconductor industry is widely acknowledged, it is only recently that the production planning and scheduling problems encountered in this environment have begun to be addressed using industrial engineering and operations research.techniques. These problems have several features that make them difficult and challenging: random yields and rework, complex product flows, and rapidly changing products and technologies. Hence their solution will contribute considerably to die theory and practice of production planning and control. In a two-part project we present a review of research in this area to date, discuss the applicability of the various approaches and suggest directions for future research. In this paper, Part I, we describe the characteristics of the semiconductor manufacturing environment and review models related to performance evaluation and production planning. Part II will review research on shop-floor control in this industry to date.}, number={4}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Uzsoy, Reha and Lee, Chung Yee and Martin Vega, Louis A.}, year={1992}, month={Sep}, pages={47–60} }
 @misc{uzsoy_1992, title={A Scheduling System Architecture for Semiconductor Testing Facilities}, author={Uzsoy, R.}, year={1992}, month={Aug} }
 @misc{uzsoy_1992, title={A Scheduling System Architecture for Semiconductor Testing Facilities}, author={Uzsoy, R.}, year={1992}, month={Apr} }
 @inproceedings{uzsoy_ovacik_1992, title={A Scheduling System Architecture for Semiconductor Testing Facilities}, author={Uzsoy, R. and Ovacik, I.}, year={1992}, month={Jan} }
 @inproceedings{ovacik_uzsoy_1992, title={A Scheduling System Architecture for Semiconductor Testing Operations}, author={Ovacik, I. and Uzsoy, R.}, year={1992}, month={Apr} }
 @inproceedings{church_ovacik_uzsoy_1992, title={A Shifting Bottleneck Methodology for Dynamic Job Shops}, author={Church, L.K. and Ovacik, I.M. and Uzsoy, R.}, year={1992}, month={Nov} }
 @inproceedings{morris_ovacik_uzsoy_1992, title={A Simulated Annealing Approach to Single-Machine Scheduling with Sequence-Dependent Setup Times}, author={Morris, S.E. and Ovacik, I. and Uzsoy, R.}, year={1992}, month={Apr} }
 @article{lee_uzsoy_1992, title={A new dynamic programming algorithm for the parallel machines total weighted completion time problem}, volume={11}, ISSN={0167-6377}, url={http://dx.doi.org/10.1016/0167-6377(92)90035-2}, DOI={10.1016/0167-6377(92)90035-2}, abstractNote={We present an alternative dynamic programming algorithm with pseudopolynomial complexity for the problem of minimizing total weighted completion time on parallel identical machines. The algorithm is polynomial in the sum of all job weights, unlike the classical approaches which are polynomial in the sum of processing times.}, number={2}, journal={Operations Research Letters}, publisher={Elsevier BV}, author={Lee, Chung-Yee and Uzsoy, Reha}, year={1992}, month={Mar}, pages={73–75} }
 @article{ovacik_uzsoy_1992, title={A shifting bottleneck algorithm for scheduling semiconductor testing operations}, volume={02}, ISSN={0960-3131}, url={http://dx.doi.org/10.1142/s0960313192000157}, DOI={10.1142/s0960313192000157}, abstractNote={In this paper we present a shifting bottleneck algorithm for scheduling semiconductor testing operations. The algorithm uses global information on the entire state of the shopfloor and a workcenter-based decomposition approach. Workcenters are scheduled one at a time in order of decreasing criticality until a schedule for the entire shop has been developed. The interactions between workcenters are captured using a disjunctive graph representation of the problem. We describe an implementation of two variants of this procedure and compare their performance against that of a number of dispatching rules. Our results show that one of the shifting bottleneck algorithms performs significantly better than all the dispatching rules within reasonable computation times.}, number={03}, journal={Journal of Electronics Manufacturing}, publisher={World Scientific Pub Co Pte Lt}, author={Ovacik, Irfan M. and Uzsoy, Reha}, year={1992}, month={Sep}, pages={119–134} }
 @inproceedings{church_uzsoy_1992, title={Analysis of Periodic and Event-Driven Rescheduling Policies in Dynamic Shops}, author={Church, L.K. and Uzsoy, R.}, year={1992}, month={Apr} }
 @inproceedings{church_uzsoy_1992, title={Analysis of Periodic and Event-Driven Rescheduling Policies in Dynamic Shops}, booktitle={Proceedings of the First Industrial Engineering Research Conference}, author={Church, L.K. and Uzsoy, R.}, editor={Klutke, G.A. and Mitta, D.A. and Ninaji, B.O. and Seiford, L.M.Editors}, year={1992}, month={May}, pages={395–399} }
 @article{church_uzsoy_1992, title={Analysis of periodic and event-driven rescheduling policies in dynamic shops}, volume={5}, ISSN={0951-192X 1362-3052}, url={http://dx.doi.org/10.1080/09511929208944524}, DOI={10.1080/09511929208944524}, abstractNote={Abstract We address the problem of rescheduling production systems in the face of dynamic job arrivals. Using simple single-and parallel-machine models to gain insight, we provide worst-case and computational analyses of periodic and event-driven rescheduling policies. Our results indicate that event-driven policies can obtain high-quality schedules with less rescheduling than continuous rescheduling policies. We also show that if structure in the job arrival process is exploited very effective periodic rescheduling policies can be designed.}, number={3}, journal={International Journal of Computer Integrated Manufacturing}, publisher={Informa UK Limited}, author={Church, Laura K. and Uzsoy, Reha}, year={1992}, month={May}, pages={153–163} }
 @article{ulusoy_uzsoy_1992, title={Computer-Aided Process Planning and Material Requirements Planning: First Steps towards Computer-Integrated Manufacturing}, volume={22}, ISSN={0092-2102 1526-551X}, url={http://dx.doi.org/10.1287/inte.22.2.76}, DOI={10.1287/inte.22.2.76}, abstractNote={ We developed a computer-aided process planning system for a firm manufacturing domestic appliances and integrated it with the existing MRP system. The system has completely replaced the previous manual system and has led to an increase in computer applications in the firm's engineering departments. }, number={2}, journal={Interfaces}, publisher={Institute for Operations Research and the Management Sciences (INFORMS)}, author={Ulusoy, Gündüz and Uzsoy, Reha}, year={1992}, month={Apr}, pages={76–86} }
 @inproceedings{lee_martin-vega_uzsoy_1992, title={Decision Support System for Dynamic Job Shop Scheduling}, author={Lee, C.Y. and Martin-Vega, L.A. and Uzsoy, R.}, year={1992}, month={Jun} }
 @misc{uzsoy_1992, title={Decomposition Algorithms for Scheduling Complex Dynamic Job Shops}, author={Uzsoy, R.}, year={1992}, month={Nov} }
 @inproceedings{uzsoy_church_ovacik_hinchman_1992, place={Baltimore, MD}, title={Dispatching Rules For Semiconductor Testing Operations: A Computational Study}, url={http://dx.doi.org/10.1109/iemt.1992.639903}, DOI={10.1109/iemt.1992.639903}, abstractNote={In this paper we compare the performance of different dispatching rules in a semiconductor testing environment for a variety of due-date and cycle time related performance measures. We also examine the effect of different models of job arrivals and uncertainties in the problem data on the performance of the dispatching rules. Our results indicate that no one rule performs well for all performance measures, and that performanceis robust to uncertainties and non-homogeneity in the arrival process.}, booktitle={Thirteenth IEEE/CHMT International Electronics Manufacturing Technology Symposium}, publisher={IEEE}, author={Uzsoy, R. and Church, L.K. and Ovacik, I.M. and Hinchman, J.}, year={1992}, pages={272–276} }
 @article{lee_uzsoy_martin-vega_1992, title={Efficient Algorithms for Scheduling Semiconductor Burn-In Operations}, volume={40}, ISSN={0030-364X 1526-5463}, url={http://dx.doi.org/10.1287/opre.40.4.764}, DOI={10.1287/opre.40.4.764}, abstractNote={ In this paper, we study the problem of scheduling semiconductor burn-in operations, where burn-in ovens are modeled as batch processing machines. A batch processing machine is one that can process up to B jobs simultaneously. The processing time of a batch is equal to the largest processing time among all jobs in the batch. We present efficient dynamic programming-based algorithms for minimizing a number of different performance measures on a single batch processing machine. We also present heuristics for a number of problems concerning parallel identical batch processing machines and we provide worst case error bounds. }, number={4}, journal={Operations Research}, publisher={Institute for Operations Research and the Management Sciences (INFORMS)}, author={Lee, Chung-Yee and Uzsoy, Reha and Martin-Vega, Louis A.}, year={1992}, month={Aug}, pages={764–775} }
 @inproceedings{avramidis_o'cinneide_uzsoy_vitharana_1992, title={Exact and Approximate Algorithms for Scheduling Batch Processing Machines}, author={Avramidis, A. and O'Cinneide, C.A. and Uzsoy, R. and Vitharana, P.}, year={1992}, month={Nov} }
 @inproceedings{chandru_lee_uzsoy_1992, title={Minimizing Total Completion Time on Batch Processing Machines}, author={Chandru, V. and Lee, C.Y. and Uzsoy, R.}, year={1992}, month={Apr} }
 @misc{uzsoy_1992, title={Production Planning and Scheduling in the Semiconductor Industry}, author={Uzsoy, R.}, year={1992}, month={Aug} }
 @inproceedings{traub_chand_uzsoy_1992, title={Rolling Horizon Algorithms for Scheduling Problems with Dynamic Arrivals}, author={Traub, R. and Chand, S. and Uzsoy, R.}, year={1992}, month={Nov} }
 @misc{uzsoy_lee_martin-vega_hinchman_1992, title={Scheduling Semiconductor Test Operations: Optimization and Approximation}, ISBN={9783642775390 9783642775376}, url={http://dx.doi.org/10.1007/978-3-642-77537-6_11}, DOI={10.1007/978-3-642-77537-6_11}, journal={New Directions for Operations Research in Manufacturing}, publisher={Springer Berlin Heidelberg}, author={Uzsoy, Reha and Lee, Chung-Yee and Martin-Vega, Louis A. and Hinchman, Jim}, year={1992}, pages={179–199} }
 @article{uzsoy_lee_martin-vega_1992, title={Scheduling semiconductor test operations: Minimizing maximum lateness and number of tardy jobs on a single machine}, volume={39}, ISSN={0894-069X 1520-6750}, url={http://dx.doi.org/10.1002/1520-6750(199204)39:3<369::aid-nav3220390307>3.0.co;2-f}, DOI={10.1002/1520-6750(199204)39:3<369::aid-nav3220390307>3.0.co;2-f}, abstractNote={We examine a class of single-machine scheduling problems with sequence-dependent setup times that arise in the context of semiconductor test operations. We present heuristics for the problems of minimizing maximum lateness with dynamic arrivals and minimizing number of tardy jobs. We exploit special problem structure to derive worst-case error bounds. The special problem structure also enables us to derive dynamic programming procedures for the problems where all jobs are available simultaneously.}, number={3}, journal={Naval Research Logistics}, publisher={Wiley}, author={Uzsoy, Reha and Lee, Chung-Yee and Martin-Vega, Louis A.}, year={1992}, month={Apr}, pages={369–388} }
 @misc{uzsoy_1991, title={A Scheduling System Architecture for Semiconductor Testing Facilities}, author={Uzsoy, R.}, year={1991}, month={Oct} }
 @misc{uzsoy_1991, title={A Scheduling System Architecture for Semiconductor Testing Facilities}, author={Uzsoy, R.}, year={1991}, month={Sep} }
 @inproceedings{uzsoy_lee_martin-vega_1991, title={A Survey of Production Planning and Scheduling in the Semiconductor Industry}, author={Uzsoy, R. and Lee, C.Y. and Martin-Vega, L.A.}, year={1991}, month={May} }
 @inproceedings{ovacik_piercefield_uzsoy_1991, title={An Approximation Methodology for Scheduling Semiconductor Testing Operations}, author={Ovacik, I. and Piercefield, S.A. and Uzsoy, R.}, year={1991}, month={Nov} }
 @article{uzsoy_ramcharan_martin-vega_1991, title={An experimental expert system for process planning of sheet-metal parts}, volume={20}, ISSN={0360-8352}, url={http://dx.doi.org/10.1016/0360-8352(91)90040-d}, DOI={10.1016/0360-8352(91)90040-d}, abstractNote={This paper presents an experimental expert system for process planning of sheet-metal parts. A basic framework for representing the necessary expert knowledge and part geometry information is outlined. The system, which is developed in Turbo Prolog and implemented for the planning of simple bent and punched parts, is described. Directions for further research are also examined.}, number={1}, journal={Computers & Industrial Engineering}, publisher={Elsevier BV}, author={Uzsoy, Reha and Ramcharan, David J. and Martin-Vega, Louis A.}, year={1991}, month={Jan}, pages={59–69} }
 @article{uzsoy_martin-vega_lee_leonard_1991, title={Production scheduling algorithms for a semiconductor test facility}, volume={4}, ISSN={0894-6507}, url={http://dx.doi.org/10.1109/66.97809}, DOI={10.1109/66.97809}, abstractNote={The authors develop production scheduling algorithms for semiconductor test operations. The operations in the facility under study are characterized by a broad product mix, variable lot sizes and yields, long and variable setup times, and limited test equipment capacity. The approach presented starts by dividing the facility or job shop into a number of work centers. The method then proceeds to sequence one work center at a time. A disjunctive graph representation of the entire facility is used to capture interactions between work centers. The introduction of different management objectives leads to different work center problems and different production scheduling algorithms. The authors present algorithms for two different work center problems. Direction for future research are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>}, number={4}, journal={IEEE Transactions on Semiconductor Manufacturing}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Uzsoy, R. and Martin-Vega, L.A. and Lee, C.-Y. and Leonard, P.A.}, year={1991}, pages={270–280} }
 @inproceedings{uzsoy_lee_ovacik_1991, title={Scheduling Parallel Semiconductor Test Systems}, author={Uzsoy, R. and Lee, C.Y. and Ovacik, I.}, year={1991}, month={May} }
 @inproceedings{uzsoy_ashby_kamin_wilson_1991, title={Scheduling and Order Release in a Make-to-Order Shop}, author={Uzsoy, R. and Ashby, J.R. and Kamin, P. and Wilson, J.R.}, year={1991}, month={Nov} }
 @inproceedings{traub_chand_uzsoy_1991, title={Sequencing in Large Flowshops to Minimize Completion Time}, author={Traub, R. and Chand, S. and Uzsoy, R.}, year={1991}, month={Nov} }
 @inproceedings{uzsoy_martin-vega_1990, title={Modelling Kanban-Based Demand-Pull Systems: A Survey and Critique}, booktitle={Proceedings, Manufacturing International '90}, author={Uzsoy, R. and Martin-Vega, L.A.}, year={1990}, month={Mar} }
 @article{uzsoy_martin-vega_1990, title={Modelling Kanban-Based Demand-Pull Systems: A Survey and Critique}, volume={3}, journal={Manufacturing Review}, author={Uzsoy, R. and Martin-Vega, L.A.}, year={1990}, pages={1–6} }
 @misc{uzsoy_1990, title={Scheduling Algorithms for Batch Processing Machines}, author={Uzsoy, R.}, year={1990}, month={Nov} }
 @inproceedings{lee_uzsoy_martin-vega_1990, title={Scheduling Algorithms for Batch Processing Machines}, author={Lee, C.Y. and Uzsoy, R. and Martin-Vega, L.A.}, year={1990}, month={Oct} }
 @inproceedings{uzsoy_lee_martin-vega_1990, title={Scheduling Algorithms for Semiconductor Test Equipment}, author={Uzsoy, R. and Lee, C.Y. and Martin-Vega, L.A.}, year={1990}, month={Oct} }
 @inproceedings{uzsoy_lee_martin-vega_1990, title={Scheduling Semiconductor Test Operations: Minimizing Maximum Lateness and Number of Tardy Jobs on a Single Machine}, author={Uzsoy, R. and Lee, C.Y. and Martin-Vega, L.A.}, year={1990}, month={Apr} }
 @misc{uzsoy_1990, title={Scheduling Semiconductor Testing Operations}, author={Uzsoy, R.}, year={1990}, month={Apr} }
 @misc{uzsoy_1990, title={Scheduling Semiconductor Testing Operations}, author={Uzsoy, R.}, year={1990}, month={Feb} }
 @inproceedings{uzsoy_martin-vega_brown_leonard_1989, place={San Mateo, CA}, title={Production scheduling algorithms for a semiconductor test facility}, url={http://dx.doi.org/10.1109/ismss.1989.77238}, DOI={10.1109/ismss.1989.77238}, abstractNote={The operations in the facility under study are characterized by a broad product mix, variable lot sizes and yields, long and variable setup times, and limited test equipment capacity. The assignment of products to testers varies depending on device and package type as well as temperature. The proposed approach starts with the division of the facility or job shop into a number of workcenters. The workcenters are then sequenced one workcenter at a time. A disjunctive graph representation of the entire facility is used to capture interactions between workcenters. The introduction of different management objectives leads to different workcenter problems and different production scheduling algorithms. Algorithms for two different workcenter problems are presented. Directions for future research are also discussed.<<ETX>>}, publisher={IEEE}, author={Uzsoy, R. and Martin-Vega, L.A. and Brown, S.M. and Leonard, P.A.}, year={1989} }
 @inproceedings{uzsoy_martin-vega_1989, title={Scheduling Semiconductor Test Facilities}, author={Uzsoy, R. and Martin-Vega, L.A.}, year={1989}, month={Oct} }
 @misc{martin-vega_uzsoy_1989, title={Scheduling Theory}, author={Martin-Vega, L.A. and Uzsoy, R.}, year={1989}, month={Apr} }
 @inproceedings{ulusoy_uzsoy_turfanda_alatli_uzuner_1986, title={An Application of Computer-Aided Process Planning}, booktitle={Proceedings of the 2nd National Conference on Machine Design and Production}, author={Ulusoy, G. and Uzsoy, R. and Turfanda, I. and Alatli, L. and Uzuner, M.}, year={1986}, month={Sep} }
 @inproceedings{ulusoy_uzsoy_turfanda_1986, title={Computer-Aided Process Planning}, booktitle={Proceedings of the 3rd National Computer Conference, Istanbul,Turkey}, author={Ulusoy, G. and Uzsoy, R. and Turfanda, I.}, year={1986}, month={Apr} }
 @article{uzsoy_1985, title={A Survey of Heuristic Algorithms}, volume={4}, journal={Sanayi Muhendisligi}, author={Uzsoy, R.}, year={1985}, month={Sep}, pages={20–22} }
 @article{uzsoy_1984, title={Decision Theory: An Introduction}, volume={3}, journal={Sanayi Muhendisligi}, author={Uzsoy, R.}, year={1984}, month={Jul}, pages={8–10} }