@article{luo_fang_zhang_king_2023, title={Price competition and cost efficiency facing buyer's bounded rationality}, volume={266}, ISSN={["1873-7579"]}, url={https://doi.org/10.1016/j.ijpe.2023.109062}, DOI={10.1016/j.ijpe.2023.109062}, abstractNote={This paper studies a pricing game in which two sellers compete to sell a product to a customer with bounded rationality. The sellers have different production costs in determining their respective prices to offer to the buyer. The buyer prefers the seller offering a lower price, but may suffer from some behavioral noises, such as bias, peer pressure and incapability, that lead the buyer to choose the seller offering a higher price with certain probability. In this sense, the buyer's choice under bounded rationality is characterized in a probabilistic model. We find that if the buyer is mildly affected by bounded rationality, the seller with a lower production cost will lower the price to increase the probability to be chosen, but will increase the price for a better profit margin as the bounded rationality level increases. On the contrary, the seller with a higher production cost always enhances the price facing the buyer's bounded rationality. Buyer's bounded rationality is a driving factor for sellers' price dispersion. Interestingly, we show that the bounded rationality, traditionally viewed as a performance-degrading impediment, may potentially lead to an unexpectedly higher payoff for the buyer. However, buyer's bounded rationality is always detrimental to the social welfare as a whole. We also extend the results to the case with multiple sellers and show that the sellers will ask for even lower prices when the buyer has an outside option.}, journal={INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS}, author={Luo, Sha and Fang, Shu-Cherng and Zhang, Jiahua and King, Russell E.}, year={2023}, month={Dec} }
 @article{nelson_werner_kay_king_mcconnell_thoney-barletta_2023, title={Two-stage stochastic programming model of US Army aviation allocation of utility helicopters to task forces}, volume={11}, ISSN={["1557-380X"]}, url={https://doi.org/10.1177/15485129231209039}, DOI={10.1177/15485129231209039}, abstractNote={ US Army aviation units often organize into task forces to meet mission requirements. The manner in which they allocate assets affects their long-term capabilities to provide aviation support. We propose a model to allocate utility helicopters across geographically separated task forces to minimize the total time of flight and unsupported air movement air mission requests (AMRs) by priority level. We model the allocation problem with a two-stage stochastic program, with the first-stage problem allocating a fleet’s helicopter teams to task forces. The stochastic demand for each task force is then revealed. The second-stage US Army aviation air movement operations planning problem is modeled as a stochastic mixed integer linear program (MILP). A practical application uses the air movement operations planning heuristic to solve the second-stage problem at scale and generate an optimal stochastic solution task force allocation. This paper provides evidence for the practical use of the proposed two-stage stochastic programming model for US Army aviation asset allocation by military decision-makers. Furthermore, this research provides a novel first formulation of a stochastic programming dial-a-ride problem with multinode refuel and a sound framework for military aviation asset allocation decision-making. }, journal={JOURNAL OF DEFENSE MODELING AND SIMULATION-APPLICATIONS METHODOLOGY TECHNOLOGY-JDMS}, author={Nelson, Russell J. and Werner, Jack and Kay, Michael G. and King, Russell E. and McConnell, Brandon M. and Thoney-Barletta, Kristin}, year={2023}, month={Nov} }
 @article{luo_ahiska_fang_king_warsing_wu_2021, title={An analysis of optimal ordering policies for a two-supplier system with disruption risk}, volume={105}, url={https://doi.org/10.1016/j.omega.2021.102517}, DOI={10.1016/j.omega.2021.102517}, abstractNote={• Optimal policy can be proved for a two-supplier system with an unreliable supplier. • Stable (s,S) policy is robust outside of parameter conditions for optimality. • There is an easily computed condition for exclusive unreliable supplier ordering. • Optimal policies move from exclusive ordering to splitting as key parameters vary. We study a single-product, periodic-review inventory system with the presence of fixed ordering cost. There are two suppliers: One is perfectly reliable while the other offers a cost advantage but is subject to possible supply interruptions. We present a theoretical framework with mathematical proofs for the optimal ordering policy in the finite-horizon setting, which exhibits an ( s , S ) structure, but with multiple, sometimes overlapping, reorder points and order-up-to levels. Then, we analyze the limiting behavior of our ( s , S ) policy and show that both the optimal cost and ordering policy parameters converge over time. This steady-state ( s , S ) policy characterizes the optimal sourcing strategy for the infinite-horizon setting. Through computational studies, we investigate the effects of parameter changes on the optimal policy and demonstrate that our two-supplier ( s , S ) ordering policy is optimal under a wide range of system parameters beyond the conditions required in the optimality proof.}, journal={Omega - The International Journal of Management Science}, publisher={Elsevier BV}, author={Luo, Sha and Ahiska, S. Sebnem and Fang, Shu-Cherng and King, Russell E. and Warsing, Donald P., Jr. and Wu, Shuohao}, year={2021}, month={Dec}, pages={102517} }
 @article{hauser_king_wysk_harrysson_2021, title={Resource planning for direct fabrication of customized orthopedic implants using EBM technology}, volume={60}, ISSN={["1878-6642"]}, url={https://doi.org/10.1016/j.jmsy.2021.07.003}, DOI={10.1016/j.jmsy.2021.07.003}, abstractNote={Medical innovations and patient expectations are pushing healthcare toward personalized medicine. In orthopedics, the concept of patient-specific implants could be economically realized with the use of additive manufacturing. Knee and hip replacements are some of the most common musculoskeletal procedures performed in the United States. Joint replacement implants are typically offered in standard sizes and geometries. The mass customization of theses prostheses, however, can improve patient outcomes and reduce medical costs. Mass customization is not economically feasible with traditional manufacturing methods because of the high fixed tooling costs for each geometry. The freedom of design offered by additive manufacturing presents a viable production alternative for unique personal geometry. The objective of this paper is to develop two new analytic models that can be used to investigate a complex additive manufacturing supply chain. The focus of the model is to provide planning tools and a methodology for the direct production of customized orthopedic implants using electron beam melting, an additive manufacturing technology. First, a production model for an additive manufacturing-based system is created. Next, resource planning for a single customized implant system is performed using a simulation model. A queuing model is developed for rapid systems analysis. The staffing requirement predictions of the two models align closely for production of a singular, customized implant. A detailed systems analysis of an additive manufacturing supply chain is conducted to illustrate the use of these models. The queueing model is analytically tractable, so it is extended to describe the production of standard and customized versions of multiple implant families.}, journal={JOURNAL OF MANUFACTURING SYSTEMS}, publisher={Elsevier BV}, author={Hauser, Margaret and King, Russell and Wysk, Richard and Harrysson, Ola}, year={2021}, month={Jul}, pages={500–511} }
 @article{thoney_sas_joines_king_2020, title={Logistics of carpet recycling in the U.S.: designing the recycling network}, volume={2}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405000.2020.1723257}, DOI={10.1080/00405000.2020.1723257}, abstractNote={Abstract Transportation of post-consumer carpet from collection points to recycling facilities and then to the end-users of the recycled materials contributes significantly to the final costs of recycled materials. In this article, several alternative network designs for the U.S. carpet recycling systems are developed and compared in terms of network costs. In two scenarios, these networks include layers of local collection centers, recycling plants, and markets for recycled materials. In the third scenario, a layer of regional collection centers is added before the recycling plants to aggregate carpet for more efficient sorting and transportation. To find the optimal number and locations of recycling plants and regional collection centers as well as the optimal flows among network facilities, a hierarchical facility location model is formulated that can be used for the different network configurations considered. To solve large-scale instances of the problem, a heuristic method based on the alternative location-allocation procedure is developed, and a computational study is conducted to assess its performance. The results of the study can be used by organizations involved in carpet recycling in the U.S. to establish reverse networks. In addition, the optimization model and the solution heuristic can be used for similar problems in forward or reverse logistics.}, journal={The Journal of The Textile Institute}, publisher={Informa UK Limited}, author={Thoney, Kristin A. and Sas, Iurii and Joines, Jeffrey A. and King, Russell E.}, year={2020}, month={Feb}, pages={1–11} }
 @article{kearby_winz_hodgson_kay_king_mcconnell_2020, title={Modeling and transportation planning for US noncombatant evacuation operations in South Korea}, volume={4}, ISSN={2399-6439 2399-6439}, url={http://dx.doi.org/10.1108/JDAL-05-2019-0010}, DOI={10.1108/JDAL-05-2019-0010}, abstractNote={
Purpose
The purpose of this paper is to investigate US noncombatant evacuation operations (NEO) in South Korea and devise planning and management procedures that improve the efficiency of those missions.


Design/methodology/approach
It formulates a time-staged network model of the South Korean noncombatant evacuation system as a mixed integer linear program to determine an optimal flow configuration that minimizes the time required to complete an evacuation. This solution considers the capacity and resource constraints of multiple transportation modes and effectively allocates the limited assets across a time-staged network to create a feasible evacuation plan. That solution is post-processed and a vehicle routing procedure then produces a high resolution schedule for each individual asset throughout the entire duration of the NEO.


Findings
This work makes a clear improvement in the decision-making and resource allocation methodology currently used in a NEO on the Korea peninsula. It immediately provides previously unidentifiable information regarding the scope and requirements of a particular evacuation scenario and then produces an executable schedule for assets to facilitate mission accomplishment.


Originality/value
The significance of this work is not relegated only to evacuation operations on the Korean peninsula; there are numerous other NEO and natural disaster related scenarios that can benefit from this approach.
}, number={1}, journal={Journal of Defense Analytics and Logistics}, publisher={Emerald}, author={Kearby, John A. and Winz, Ryan D. and Hodgson, Thom J. and Kay, Michael G. and King, Russell E. and McConnell, Brandon M.}, year={2020}, month={Feb}, pages={41–69} }
 @article{mcconnell_hodgson_kay_king_liu_parlier_thoney-barletta_wilson_2019, title={Assessing uncertainty and risk in an expeditionary military logistics network}, volume={7}, ISSN={1548-5129 1557-380X}, url={http://dx.doi.org/10.1177/1548512919860595}, DOI={10.1177/1548512919860595}, abstractNote={ Uncertainty is rampant in military expeditionary operations spanning high-intensity combat to humanitarian operations. These missions require rapid planning and decision-support tools to address the logistical challenges involved in providing support in often austere environments. The US Army’s adoption of an enterprise resource planning system provides an opportunity to develop automated decision-support tools and other analytical models designed to take advantage of newly available logistical data. This research presents a tool that runs in near-real time to assess risk while conducting capacity planning and performance analysis designed for inclusion in a suite of applications dubbed the Military Logistics Network Planning System, which previously only evaluated the mean sample path. Logistical data from combat operations during Operation Iraqi Freedom drive supply requisition forecasts for a contingency scenario in a similar geographic environment. A nonstationary queueing network model is linked with a heuristic logistics scheduling methodology to provide a stochastic framework to account for uncertainty and assess risk. }, number={2}, journal={The Journal of Defense Modeling and Simulation: Applications, Methodology, Technology}, publisher={SAGE Publications}, author={McConnell, Brandon M and Hodgson, Thom J and Kay, Michael G and King, Russell E and Liu, Yunan and Parlier, Greg H and Thoney-Barletta, Kristin and Wilson, James R}, year={2019}, month={Jul}, pages={154851291986059} }
 @article{nagulpelli_king_warsing_2019, title={Integrated traditional and additive manufacturing production profitability model}, volume={34}, ISSN={["2351-9789"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85072391087&partnerID=MN8TOARS}, DOI={10.1016/j.promfg.2019.06.121}, abstractNote={Production decision-makers now have a choice of production technologies. Decision-makers are familiar with "Traditional Manufacturing" (TM) technologies. In favorable circumstances, emerging "Additive Manufacturing" (AM) technology now offers more flexibility to modify the manufacturing environment and improve production logistics efficiency to enhance profits over a production schedule. This paper presents research, process methodologies, and a practical approach to the profit-based economic decision-modelling for production planning in a manufacturing environment resourced with both TM and AM technologies. The research identifies a framework for production leaders and managers to implement efficiency measures while adapting or refining AM production in an existing TM production environment. The paper also outlines opportunities for future research toward the objective of optimizing production technology assignments within a mixed-resource manufacturing environment.}, journal={47TH SME NORTH AMERICAN MANUFACTURING RESEARCH CONFERENCE (NAMRC 47)}, author={Nagulpelli, Kimberly S. and King, Russell E. and Warsing, Donald}, year={2019}, pages={619–630} }
 @article{rogers_mcconnell_hodgson_kay_king_parlier_thoney barletta_2018, title={A Military Logistics Network Planning System}, volume={23}, url={http://www.lib.ncsu.edu/resolver/1840.20/36268}, DOI={10.5711/1082598323405}, number={4}, journal={Military Operations Research}, author={Rogers, Matthew B. and McConnell, Brandon M. and Hodgson, Thom J. and Kay, Michael G. and King, Russell E. and Parlier, Greg and Thoney Barletta, Kristen}, year={2018}, pages={5–24} }
 @article{warsing_wangwatcharakul_king_2019, title={Computing base-stock levels for a two-stage supply chain with uncertain supply}, volume={89}, ISSN={0305-0483}, url={http://dx.doi.org/10.1016/J.OMEGA.2018.10.001}, DOI={10.1016/j.omega.2018.10.001}, abstractNote={We consider independent decision makers in a two-stage supply chain subject to uncertainty in upstream supply, and we use a recently published computational algorithm to generate independent, single-stage (ISS) base-stock inventory solutions for each stage in the system. These solutions are computed by employing straightforward, linear functions to estimate the parameters that must be set to seed the single-stage computational algorithm. Those linear functions are derived from the system-optimal solutions, which are found by solving a Markov chain model of the two-stage system. We demonstrate that the ISS solutions are often quite close to the system-optimal solution, and moreover, we develop a fast, descent-based search to quickly find the system-optimal solutions starting from the ISS solutions. We use our solution algorithm to generate optimal solutions to 1100 randomly-generated problem instances, allowing us to explore the behavior of the two-stage inventory system under various cost, demand uncertainty, and supply uncertainty conditions. We find that the downstream stocking levels are strongly influenced by the properties of the downstream demand, while the upstream stocking level is very strongly influenced by the holding costs and supply uncertainty, and only marginally by the retailer penalty cost. Moreover, the system responds to changes in the cost and uncertainty environment mostly by shifting the burden of holding cost either upstream or downstream, leaving the downstream penalty cost relative stable across the large set of problem instances we study.}, journal={Omega}, publisher={Elsevier BV}, author={Warsing, Donald P., Jr. and Wangwatcharakul, Worawut and King, Russell E.}, year={2019}, month={Dec}, pages={92–109} }
 @article{kim_hodgson_king_liu_kay_2017, title={Allocation heuristics for high-altitude long- endurance UAV image intelligence platforms}, volume={22}, number={3}, journal={Military Operations Research}, author={Kim, G. and Hodgson, T. J. and King, R. E. and Liu, Y. N. and Kay, M. G.}, year={2017}, pages={5–19} }
 @article{ahiska_gocer_king_2017, title={Heuristic inventory policies for a hybrid manufacturing/remanufacturing system with product substitution}, volume={114}, ISSN={["1879-0550"]}, DOI={10.1016/j.cie.2017.10.014}, abstractNote={We consider inventory control for an infinite-horizon hybrid manufacturing/remanufacturing system with product substitution under stochastic demand and returns. Remanufactured and manufactured products are considered as different products having different costs and selling prices as well as separate demand streams. Remanufactured products have a higher stock out risk than manufactured products because the remanufacturing capacity is dependent on available returns for remanufacture. One way to cope with this stock-out risk is to use a downward substitution strategy, under which a manufactured product (i.e. higher value item) substitutes for a remanufactured product (i.e. lower value item) in case the latter runs out of stock. This problem can be formulated as a Markov Decision Process in order to determine the optimal manufacturing and remanufacturing decisions under product substitution. However, the optimal policy has a complicated structure. Based on characterization of the optimal policies, we propose intuitive heuristic policies that are easy to implement in practice. Then, we develop a heuristic search technique to determine the parameter values for these policies in an efficient way. We evaluate the performance of the proposed heuristic policies compared to the optimal inventory policy through a real case study involving a spare part manufacturer.}, journal={COMPUTERS & INDUSTRIAL ENGINEERING}, author={Ahiska, S. Sebnem and Gocer, Fethullah and King, Russell E.}, year={2017}, month={Dec}, pages={206–222} }
 @article{hussein_hodgson_king_jackson_thoney barletta_2016, title={Forecasting communications technology products with leading economic indicators}, volume={35}, number={3}, journal={Journal of Business Forecasting}, author={Hussein, J. and Hodgson, T.J. and King, R.E. and Jackson, S.D. and Thoney Barletta, K.A.}, year={2016}, pages={21–23, 26–27} }
 @inproceedings{shouche_wysk_king_harrysson_2016, title={Supply chain operations reference model for us based powder bed metal additive manufacturing processes}, DOI={10.1109/wsc.2016.7822173}, abstractNote={This paper focuses on modeling the supply chain of an additively manufactured, uniquely customized Total Hip Replacement implant. It explores how the supply chain could be modeled for hip components which are customized for individual patients and produced using additive manufacturing processes. The concept of the SCOR (Supply Chain Operations Reference) model is used to create a formal model of this system. The SCOR model is used to compare the traditional and the AM supply chain on the basis of different performance metrics. The formal supply chain model is used to extract operational activities so that a computer simulation model of the system can be developed. The simulation is used to model system performance so that bottleneck operations can be identified and source needs determined along with a sensitivity analysis to analyze how change in times and resources affect production quantities.}, booktitle={2016 winter simulation conference (wsc)}, author={Shouche, S. and Wysk, R. A. and King, Russell and Harrysson, O. L. A.}, year={2016}, pages={1158–1169} }
 @inbook{gocer_ahiska_king_2015, place={Cham, Switzerland}, series={Communications in Computer and Information Science}, title={Analysis of a Downward Substitution Strategy in a Manufacturing/Remanufacturing System}, ISBN={9783319175089 9783319175096}, ISSN={1865-0929 1865-0937}, url={http://dx.doi.org/10.1007/978-3-319-17509-6_13}, DOI={10.1007/978-3-319-17509-6_13}, abstractNote={A hybrid production system is considered where both manufacture of new product and remanufacture of returned items is performed. Due to consumer perception, new and remanufactured products are treated as different products with different costs and selling prices as well as separate demand streams. Remanufactured products have a higher stock out risk because the remanufacturing capacity is limited by the amount of returns available for remanufacture. One way to cope with this risk is to use a downward substitution strategy, i.e. a higher valued manufactured product is substituted for an out of stock lower valued remanufactured product. We formulate this control problem as an infinite-horizon hybrid manufacturing/remanufacturing system with product substitution under stochastic demand and returns. We model it as a Markov Decision Process in order to determine the optimal manufacturing and remanufacturing decisions under product substitution. The effects of stochastic demand/return distributions on the profitability of the substitution strategy are investigated through numerical experimentation.}, booktitle={Operations Research and Enterprise Systems}, publisher={Springer International Publishing}, author={Gocer, Fethullah and Ahiska, S. Sebnem and King, Russell E.}, editor={Pinson, E. and Valente, F. and Vitoriano, B.Editors}, year={2015}, pages={186–198}, collection={Communications in Computer and Information Science} }
 @inproceedings{gocer_ahiska_king_2015, title={Analysis of a downward substitution strategy in a manufacturing/remanufacturing system}, volume={509}, booktitle={Operations research and enterprise systems, icores 2014}, author={Gocer, F. and Ahiska, S. S. and King, R. E.}, year={2015}, pages={186–198} }
 @article{ahiska_king_2015, title={Inventory policy characterisation methodologies for a single-product recoverable manufacturing system}, volume={9}, ISSN={1751-5254 1751-5262}, url={http://dx.doi.org/10.1504/EJIE.2015.068652}, DOI={10.1504/ejie.2015.068652}, abstractNote={We consider the production/inventory control for a recoverable system with stochastic demand and returns where stock is replenished by manufacturing new items or remanufacturing returned items. The optimal control policy found by solving a Markov decision process (MDP) for a given problem instance can be represented by a list of the optimal manufacturing and remanufacturing decisions for each possible inventory state. This list does not provide any general structure or insight for the optimal control nor is it practical for implementation. We propose two heuristic methodologies which can be used together to provide intuitive, easy to implement, near-optimal to optimal policies. This allows the policy for new scenarios to be determined without requiring solution of the MDP model. Results from a numerical experimentation show that the characterisations provided by our proposed methodologies represent the optimal inventory policies well with small deviations from optimal cost. [Received 9 March 2013; Revised 15 July 2013; Revised 20 November 2013; Accepted 1 January 2014]}, number={2}, journal={European J. of Industrial Engineering}, publisher={Inderscience Publishers}, author={Ahiska, Semra Sebnem and King, Russell E.}, year={2015}, pages={222} }
 @article{hanson_hodgson_kay_king_thoney-barletta_2015, title={On the economic lot scheduling problem: stock-out prevention and system feasibility}, volume={53}, ISSN={["1366-588X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84932193491&partnerID=MN8TOARS}, DOI={10.1080/00207543.2015.1005246}, abstractNote={The Economic Lot Scheduling Problem is a classical scheduling problem with the objective of minimising the long-run inventory and set-up costs of a single machine, multi-product inventory system. Demand rates, production rates and set-up times are assumed to be deterministic. The problem has been extensively studied and methods exist to obtain cyclic schedules which minimise total cost. In order to apply a cyclic schedule without a stock-out occurring, certain initial inventory levels are required. This paper considers the scenario where inventory levels are critically low and the cyclic schedule cannot be applied. Analytical methods are developed to determine: if the initial inventory is sufficient to prevent a stock-out from occurring; the maximum time until a stock-out will occur if a stock-out is unavoidable; and the minimum time required to obtain the necessary inventory to resume the cyclic schedule if a stock-out can be avoided.}, number={16}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, publisher={Informa UK Limited}, author={Hanson, Brian B. and Hodgson, Thom J. and Kay, Michael G. and King, Russell E. and Thoney-Barletta, Kristin A.}, year={2015}, month={Aug}, pages={4903–4916} }
 @article{sas_thoney_joines_king_woolard_2015, title={Reverse Logistics of US Carpet Recycling}, volume={1}, ISBN={["978-3-319-12702-6"]}, ISSN={["2365-6395"]}, DOI={10.1007/978-3-319-12703-3_1}, abstractNote={A high volume of post-consumer carpet (PCC) is discarded each year in the USA, placing significant pressure on landfills and leading to the loss of valuable materials contained in carpets. To explain factors that influence landfill diversion rates for different types of products, an overview of the reverse logistics framework in the literature is provided. The framework is used to analyze the current state of carpet recycling in the USA, and PCC recycling is shown to be a typical material recovery network. Therefore, because PCC recycling requires a high volume of carpet to be collected and transportation costs to be minimized for it to be economical, a well-organized reverse logistics network is critical. In this respect, a review of reverse network design studies for different products is provided and research conducted to design PCC collection and recycling networks is discussed in detail.}, journal={SUSTAINABLE FASHION SUPPLY CHAIN MANAGEMENT: FROM SOURCING TO RETAILING}, publisher={Cham: Springer,}, author={Sas, Iurii and Thoney, Kristin A. and Joines, Jeffrey A. and King, Russell E. and Woolard, Ryan}, editor={Choi, T.C. Edwin Cheng Tsan-MingEditor}, year={2015}, pages={3–30} }
 @article{lobo_wilson_thoney_hodgson_king_2014, title={A practical method for evaluating worker allocations in large-scale dual resource constrained job shops}, volume={46}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/0740817x.2014.892231}, DOI={10.1080/0740817x.2014.892231}, abstractNote={In two recent articles, Lobo et al. present algorithms for allocating workers to machine groups in a Dual Resource Constrained (DRC) job shop so as to minimize Lmax , the maximum job lateness. Procedure LBSA delivers an effective lower bound on Lmax , while the heuristic delivers an allocation whose associated schedule has a (usually) near-optimal Lmax  value. To evaluate an HSP-based allocation’s quality in a given DRC job shop, the authors first compute the gap between HSP’s associated Lmax  value and ’s lower bound. Next they refer this gap to the distribution of a “quasi-optimality” gap that is generated as follows: (i) independent simulation replications of the given job shop are obtained by randomly sampling each job’s characteristics; and (ii) for each replication, the associated quasi-optimality gap is computed by enumerating all feasible allocations. Because step (ii) is computationally intractable in large-scale problems, this follow-up article formulates a revised step (ii) wherein each simulation invokes , an improved version of , to yield an approximation to the quasi-optimality gap. Based on comprehensive experimentation, it is concluded that the -based distribution did not differ significantly from its enumeration-based counterpart; and the revised evaluation method was computationally tractable in practice. Two examples illustrate the use of the revised method.}, number={11}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Lobo, Benjamin J. and Wilson, James R. and Thoney, Kristin A. and Hodgson, Thom J. and King, Russell E.}, year={2014}, month={Jul}, pages={1209–1226} }
 @article{bucci_woolard_joines_thoney_king_2014, title={Incorporating economies of scale into facility location problems in carpet recycling}, volume={105}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405000.2014.890833}, DOI={10.1080/00405000.2014.890833}, abstractNote={The Carpet America Recovery Effort (CARE) set a goal to divert 40% of used carpet from landfills in the United States by 2012, but only achieved a 10% diversion rate. To achieve the 40% diversion rate, approximately 1.4 billion lbs would need to have been diverted. Diverting this significant quantity may require the design of a larger, more effective reverse logistics network to process the used materials. A new facility location heuristic originally developed for the forward distribution of products is applied to the reverse logistics system for carpet recycling. The objective is to locate an unknown number of carpet recycling facilities to minimize the total cost. The model includes transportation costs, as well as fixed facility and processing costs at the recycling plant, the latter exhibiting economies of scale (EOS) as the facility size increases. We evaluate the model using data from the CARE collection network in the continental United States and compare these findings to models that assume a significant increase in collection locations and rates to meet specific carpet diversion targets. We show the impact of EOS of the recycling facilities on the solution structure, as well as the impact that collection volumes have on the solution.}, number={12}, journal={The Journal of The Textile Institute}, publisher={Informa UK Limited}, author={Bucci, Michael J. and Woolard, Ryan and Joines, Jeffrey and Thoney, Kristin and King, Russell E.}, year={2014}, month={Mar}, pages={1300–1311} }
 @article{ahiska_appaji_king_warsing_2013, title={A Markov decision process-based policy characterization approach for a stochastic inventory control problem with unreliable sourcing}, volume={144}, ISSN={["1873-7579"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84878827602&partnerID=MN8TOARS}, DOI={10.1016/j.ijpe.2013.03.021}, abstractNote={We consider a single-product periodic-review inventory system for a retailer who has adopted a dual sourcing strategy to cope with potential supply process interruptions. Orders are placed to a perfectly reliable supplier and/or to a less reliable supplier that offers a better price. The success of an order placed to the unreliable supplier depends on his supply status that has a Markovian nature. The inventory control problem for this unreliable supply chain is modeled as a discrete-time Markov decision process (MDP) in order to find the optimal ordering decisions. Through numerical experimentation, the structure of the optimal ordering policy under several cost scenarios and different supplier reliability levels is determined. Four basic policy structures are found and are referred as case 1: order only from the unreliable supplier; case 2: order simultaneously from both suppliers or only from the unreliable supplier depending on the inventory level; case 3: order from one or the other but not both suppliers simultaneously; and case 4: order only from the reliable supplier. For all cases, (s, S)-like policies characterize perfectly the optimal ordering decisions due to the existence of the fixed ordering cost. Further experimentation is done to study the effects of changes in several system parameters (cost parameters such as fixed ordering cost, unit purchasing cost, backorder cost as well as the supplier reliability level) on the ordering policy and cost of the system.}, number={2}, journal={INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS}, author={Ahiska, S. Sebnem and Appaji, Samyuktha R. and King, Russell E. and Warsing, Donald P., Jr.}, year={2013}, month={Aug}, pages={485–496} }
 @article{lobo_hodgson_king_thoney_wilson_2013, title={Allocating job-shop manpower to minimize Lmax: Optimality criteria, search heuristics, and probabilistic quality metrics}, volume={40}, ISSN={0305-0548}, url={http://dx.doi.org/10.1016/j.cor.2013.02.008}, DOI={10.1016/j.cor.2013.02.008}, abstractNote={We address questions raised by Lobo et al. in 2012 regarding the NP-hard problem of finding an optimal allocation of workers to machine groups in a job shop so as to minimize Lmax, the maximum job lateness. Lobo et al. formulated a lower bound on Lmax given a worker allocation, and an algorithm to find an allocation yielding the smallest such lower bound. In this article we establish optimality criteria to verify that a given allocation corresponds to a schedule that yields the minimum value of Lmax. For situations in which the optimality criteria are not satisfied, we present the Heuristic Search Procedure (HSP), which sequentially invokes three distinct search heuristics, the Local Neighborhood Search Strategy (LNSS), Queuing Time Search Strategy 1 (QSS1), and Queuing Time Search Strategy 2 (QSS2), before delivering the best allocation encountered by LNSS, QSS1, and QSS2. HSP is designed to find allocations allowing a heuristic scheduler to generate schedules with a smaller value of Lmax than that achieved via the allocation yielding the final lower bound of Lobo et al. Comprehensive experimentation indicated that HSP delivered significant reductions in Lmax. We also estimate a probability distribution for evaluating the quality (closeness to optimality) of an allocation delivered by a heuristic search procedure such as HSP. This distribution permits assessing the user's confidence that a given allocation will enable the heuristic scheduler to generate its best possible schedule—i.e., the schedule with the heuristic scheduler's smallest achievable Lmax value.}, number={10}, journal={Computers & Operations Research}, publisher={Elsevier BV}, author={Lobo, Benjamin J. and Hodgson, Thom J. and King, Russell E. and Thoney, Kristin A. and Wilson, James R.}, year={2013}, month={Oct}, pages={2569–2584} }
 @article{tejada_ivy_king_wilson_ballan_kay_diehl_yankaskas_2014, title={Combined DES/SD model of breast cancer screening for older women, II: screening-and-treatment simulation}, volume={46}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/0740817X.2013.851436}, DOI={10.1080/0740817x.2013.851436}, abstractNote={In the second article of a two-article sequence, the focus is on a simulation model for screening and treatment of breast cancer in U.S. women of age 65+. The first article details a natural-history simulation model of the incidence and progression of untreated breast cancer in a representative simulated population of older U.S. women, which ultimately generates a database of untreated breast cancer histories for individuals in the simulated population. Driven by the resulting database, the screening-and-treatment simulation model is composed of discrete-event simulation (DES) and system dynamics (SD) submodels. For each individual in the simulated population, the DES submodel simulates screening policies and treatment procedures to estimate the resulting survival rates and the costs of screening and treatment. The SD submodel represents the overall structure and operation of the U.S. system for detecting and treating breast cancer. The main results and conclusions are summarized, including a final recommendation for annual screening between ages 65 and 80. A discussion is also presented on how both the natural-history and screening-and-treatment simulations can be used for performance comparisons of proposed screening policies based on overall cost-effectiveness, the numbers of life-years and quality-adjusted life-years saved, and the main components of the total cost incurred by each policy.}, number={7}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Tejada, Jeremy J. and Ivy, Julie S. and King, Russell E. and Wilson, James R. and Ballan, Matthew J. and Kay, Michael G. and Diehl, Kathleen M. and Yankaskas, Bonnie C.}, year={2014}, month={Mar}, pages={707–727} }
 @article{warsing_wangwatcharakul_king_2013, title={Computing optimal base-stock levels for an inventory system with imperfect supply}, volume={40}, ISSN={0305-0548}, url={http://dx.doi.org/10.1016/j.cor.2013.04.001}, DOI={10.1016/j.cor.2013.04.001}, abstractNote={We study a single-item, single-site, periodic-review inventory system with negligible fixed ordering costs. The supplier to this system is not entirely reliable, such that each order is a Bernoulli trial, meaning that, with a given probability, the supplier delivers the current order and any accumulated backorders at the end of the current period, resulting in a Geometric distribution for the actual resupply lead time. We develop a recursive expression for the steady-state probability vector of a discrete-time Markov process (DTMP) model of this imperfect-supply inventory system. We use this recursive expression to prove the convexity of the inventory system objective function, and also to prove the optimality of our computational procedure for finding the optimal base-stock level. We present a service-constrained version of the problem and show how the computation of the optimal base-stock level using our DTMP method, incorporating the explicit distribution of demand over the lead time plus review (LTR) period, compares to approaches in the literature that approximate this distribution. We also show that the version of the problem employing an explicit penalty cost can be solved in closed-form for the optimal base-stock level for two specific period demand distributions, and we explore the behavior of the optimal base-stock level and the corresponding optimal service level under various values of the problem parameters.}, number={11}, journal={Computers & Operations Research}, publisher={Elsevier BV}, author={Warsing, Donald P., Jr. and Wangwatcharakul, Worawut and King, Russell E.}, year={2013}, month={Nov}, pages={2786–2800} }
 @article{lobo_hodgson_king_thoney_wilson_2013, title={An effective lower bound on <mml:math altimg="si0041.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd"><mml:msub><mml:mrow><mml:mi>L</mml:mi></mml:mrow><mml:mrow><mml:mi>max</mml:mi></mml:mrow></mml:msub></mml:math> in a worker-constrained job shop}, volume={40}, ISSN={0305-0548}, url={http://dx.doi.org/10.1016/j.cor.2012.07.003}, DOI={10.1016/j.cor.2012.07.003}, abstractNote={A common industrial operation is a dual resource constrained job shop where: (a) the objective is to minimize L max , the maximum job lateness; (b) machines are organized into groups; and (c) each worker is assigned to a specific machine group. Because this problem is NP-hard, finding optimal solutions by enumeration is impractical. This paper details a procedure to compute a lower bound on L max that will be used in follow-up work to effectively evaluate the absolute performance of heuristic solutions. Given an allocation of workers to machine groups, a lower bound on L max is first computed for each machine group using a network-flow formulation. The lower bound on L max for the job shop is the largest of the lower bounds for the machine groups. A search algorithm then finds a worker allocation yielding the smallest such lower bound on L max for the job shop; and the latter quantity is our proposed lower bound on L max . Given a worker allocation, we use the Virtual Factory (a heuristic scheduler developed by Hodgson et al. in 1998) to generate a schedule. Experiments with a wide variety of job shops indicated that the proposed lower bound on L max could often be achieved by a Virtual Factory schedule based on the worker allocation yielding this lower bound. However, there were problem instances for which other worker allocations enabled the Virtual Factory to generate better schedules. Follow-up work provides optimality criteria, and heuristics to find improved allocations if these criteria are not satisfied.}, number={1}, journal={Computers & Operations Research}, publisher={Elsevier BV}, author={Lobo, Benjamin J. and Hodgson, Thom J. and King, Russell E. and Thoney, Kristin A. and Wilson, James R.}, year={2013}, month={Jan}, pages={328–343} }
 @article{vila-parrish_ivy_king_abel_2012, title={Patient-based pharmaceutical inventory management: a two-stage inventory and production model for perishable products with Markovian demand}, volume={1}, ISSN={2047-6965 2047-6973}, url={http://dx.doi.org/10.1057/hs.2012.2}, DOI={10.1057/hs.2012.2}, abstractNote={Drug shortages have increased over the past decade, tripling since 2006. Pharmacy material managers are challenged with developing inventory policies given changing demand, limited suppliers, and regulations affecting supply. Pharmaceutical inventory management and patient care are inextricably linked; suboptimal control impacts both patient treatment and the cost of care. We study a perishable inventory problem motivated by challenges in pharmaceutical management. Inpatient hospital pharmacies stock medications in two stages, raw material and finished good (e.g. intravenous). While both stages of material are perishable, the finished form is highly perishable. Pharmacy demand depends on the population and patient conditions. We use a stochastic 'demand state' as a surrogate for patient condition and develop a Markov decision process to determine optimal, state-dependent two-stage inventory and production policies. We define two ordering and production scenarios, prove the existence of optimal solutions for both scenarios, and apply this framework to the management of Meropenem.}, number={1}, journal={Health Systems}, publisher={Informa UK Limited}, author={Vila-Parrish, Ana R and Ivy, Julie S and King, Russell E and Abel, Steven R}, year={2012}, month={Jun}, pages={69–83} }
 @article{davis_king_hodgson_wei_2011, title={Information sharing in capacity constrained supply chains under lost sales}, volume={49}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2010.535037}, abstractNote={We present a modelling approach for quantifying the value of information in supply chains using Markov decision processes (MDP). The case where information sharing occurs is modelled using a completely observable MDP. A restricted observation MDP is used to model the case where no information sharing occurs. We illustrate the use of this framework on a two-stage capacity-constrained supply chain consisting of a supplier and a retailer. We quantify the value of information sharing in this setting and construct several performance measures to identify the benefits to both the retailer and supplier as a result of the information sharing partnership.}, number={24}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Davis, Lauren B. and King, Russell E. and Hodgson, Thom J. and Wei, Wenbin}, year={2011}, pages={7469–7491} }
 @article{hartman_joines_thoney_king_2012, title={The effect speed and replenishment flexibility has on overall costs of sourcing apparel products}, volume={103}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405000.2011.595106}, DOI={10.1080/00405000.2011.595106}, abstractNote={This research investigates the sourcing of basic and seasonal garments as a function of lead time as well as the ability that providing in-season replenishment orders has on overall costs. Most sourcing decisions are made on the basis of the first cost of the garment with little regard to the potential impact of large hidden costs (i.e. lost sales, inventory costs, markdowns, etc.). A small survey administered to apparel manufacturers and retailers is used to gather perspectives on sourcing from various regions of the world. However, its primary purpose is to gather information and data to drive a variety of case studies. The Sourcing Simulator™ is used to determine the effect that lead times, forecasting error, product drift and seasonality have on retail performance (i.e. service levels, gross margins and inventory levels) for these case studies. Analysis is performed to attempt to quantify some of these hidden costs. Results show that choosing suppliers with shorter lead times provides significant advantages for basic goods as well as seasonal goods, which in some instances justify using more expensive suppliers in terms of first cost. These advantages take on the form of smaller inventory levels for achieving the same service, as well as minimizing the impact of errors in forecast and product mix for basic goods while increasing margins by using in-season replenishments for seasonal products.}, number={6}, journal={Journal of the Textile Institute}, publisher={Informa UK Limited}, author={Hartman, Lisa and Joines, Jeffrey A. and Thoney, Kristin A. and King, Russell E.}, year={2012}, month={Jun}, pages={604–621} }
 @inproceedings{ahıska_appaji_king_wang_warsing_2010, title={Optimal ordering policy characterization in an unreliable supply chain}, booktitle={IIE Annual Conference Proceedings}, author={Ahıska, S.Ş. and Appaji, S.R. and King, R.E. and Wang, Y. and Warsing, D.P.}, year={2010} }
 @article{ahıska_king_2009, title={Inventory control strategies in a recoverable system with state-dependent product returns}, volume={2}, number={1}, journal={Journal of Management and Engineering Integration}, author={Ahıska, S.Ş. and King, R.E.}, year={2009}, pages={1–8} }
 @article{ahiska_king_2010, title={Inventory optimization in a one product recoverable manufacturing system}, volume={124}, ISSN={["1873-7579"]}, DOI={10.1016/j.ijpe.2009.09.002}, abstractNote={Environmental regulations or the necessity for a 'green image' due to growing environmental concerns, as well as the potential economical benefits of product recovery, have pushed manufacturers to integrate product recovery management with their manufacturing process. Consequently, production planning and inventory control of recoverable manufacturing systems has gained significant interest among researchers who aim to contribute to industrial practice. This paper considers inventory optimization of a single product recoverable manufacturing system where customer demands are satisfied through either regular production (manufacturing) of new items or remanufacturing of returned items. We present robust, implementable characterizations of the optimal manufacturing/remanufacturing inventory policies found using Markov decision processes. We extend the results in the literature by considering setup costs and different lead time cases for manufacturing and remanufacturing.}, number={1}, journal={INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS}, author={Ahiska, S. Sebnem and King, Russell E.}, year={2010}, month={Mar}, pages={11–19} }
 @article{ahiska_king_2010, title={Life cycle inventory policy characterizations for a single-product recoverable system}, volume={124}, ISSN={["1873-7579"]}, DOI={10.1016/j.ijpe.2009.08.033}, abstractNote={This paper investigates the optimal inventory policies over the life cycle of a remanufacturable product. The product is produced through manufacturing or remanufacturing. Benefiting from the long-run optimal policies found through Markov decision analysis, the optimal or near-optimal policy characterizations with practical structure are determined for every life cycle stage under several setup cost configurations. The effects of changes in the demand and return rates on the optimal inventory policies are investigated through these policies. Further, a performance comparison with a PULL strategy is provided. The performance of these long-run policies is evaluated as well in a finite-horizon setting, and the importance of frequent policy revision over the product life cycle is illustrated numerically.}, number={1}, journal={INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS}, author={Ahiska, S. Sebnem and King, Russell E.}, year={2010}, month={Mar}, pages={51–61} }
 @article{vila-parrish_ivy_king_2008, title={A SIMULATION-BASED APPROACH FOR INVENTORY MODELING OF PERISHABLE PHARMACEUTICALS}, ISBN={["978-1-4244-2707-9"]}, DOI={10.1109/wsc.2008.4736234}, abstractNote={Pharmaceutical expenditures are increasing for hospital systems nationwide. We model the inventory and ordering policies for perishable drugs in the setting of an inpatient hospital pharmacy. We consider two stages of inventory: raw material and finished good (e.g. intravenous). We use a two-phased approach to explore policy structures that could be implemented in the hospital pharmacy. We develop a policy which is based on the idea that hospitals can improve both costs and patient demand fulfillment by using knowledge of patient mix to guide their drug inventory and preparation decisions. We compare this policy to a simpler stationary base stock policy. The policies are evaluated on the basis of (1) shortage cost, (2) outdating cost (expirations), and (3) holding cost through a range of cost scenarios.}, journal={2008 WINTER SIMULATION CONFERENCE, VOLS 1-5}, author={Vila-Parrish, Ana R. and Ivy, Julie Simmons and King, Russell E.}, year={2008}, pages={1532–1538} }
 @article{iser_denton_king_2008, title={HEURISTICS FOR BALANCING OPERATING ROOM AND POST-ANESTHESIA RESOURCES UNDER UNCERTAINTY}, ISBN={["978-1-4244-2707-9"]}, DOI={10.1109/wsc.2008.4736243}, abstractNote={The post-anesthesia care unit (PACU) is a shared resource in the hospital where patients recover from surgery. It is fed by a set of operating rooms (OR¿s) often spanning several surgical services. It is insufficient to determine the best surgery schedule for any single OR without considering available PACU capacity. We model this as a two-stage process where the first stage is surgery and the second, post-anesthesia recovery. An interesting aspect of the second-stage process is that it begins as soon as the first stage has concluded even if a PACU bed is not available. In this case, the OR continues to house the recovering patient until a PACU bed is available. We analyze the structure of the problem, evaluate several heuristics based on competing performance measures for surgical suite efficiency, and present results of numerical experiments and insights that can be derived from them.}, journal={2008 WINTER SIMULATION CONFERENCE, VOLS 1-5}, author={Iser, Jill H. and Denton, Brian T. and King, Russell E.}, year={2008}, pages={1601–1608} }
 @article{davis_hodgson_king_wei_2009, title={Technical Note: A Computationally Efficient Algorithm for Undiscounted Markov Decision Processes with Restricted Observations}, volume={56}, ISSN={["1520-6750"]}, DOI={10.1002/nav.20329}, abstractNote={AbstractWe present a computationally efficient procedure to determine control policies for an infinite horizon Markov Decision process with restricted observations. The optimal policy for the system with restricted observations is a function of the observation process and not the unobservable states of the system. Thus, the policy is stationary with respect to the partitioned state space. The algorithm we propose addresses the undiscounted average cost case. The algorithm combines a local search with a modified version of Howard's (Dynamic programming and Markov processes, MIT Press, Cambridge, MA, 1960) policy iteration method. We demonstrate empirically that the algorithm finds the optimal deterministic policy for over 96% of the problem instances generated. For large scale problem instances, we demonstrate that the average cost associated with the local optimal policy is lower than the average cost associated with an integer rounded policy produced by the algorithm of Serin and Kulkarni Math Methods Oper Res 61 (2005) 311–328. © 2008 Wiley Periodicals, Inc. Naval Research Logistics 2009}, number={1}, journal={NAVAL RESEARCH LOGISTICS}, author={Davis, Lauren B. and Hodgson, Thom J. and King, Russell E. and Wei, Wenbin}, year={2009}, month={Feb}, pages={86–92} }
 @article{stanfield_king_hodgson_2006, title={Determining sequence and ready times in a remanufacturing system}, volume={38}, ISSN={["0740-817X"]}, DOI={10.1080/07408170500371830}, abstractNote={A fundamental scheduling problem is to determine a production start (ready) time for jobs based on customer-specified due dates. Typically, the objective is to delay the ready time in an attempt to minimize work-in-process inventory and maximize production system utilization. In many practical situations, notably remanufacturing operations, highly variable operation times and intricate process plans complicate this problem. In such a case, a specific ready time implies a confidence of on-time completion. Prior analytical results imply the optimal solution is a function of: (i) customer due dates; (ii) desired confidence levels; and (iii) stochastic makespan minimization. This paper proposes the use of a network flow model to represent a remanufacturing flowshop and then presents a structured heuristic approach that is able to develop sequences and ready times for remanufacturing systems by balancing the three factors. A broad experimental design is used to demonstrate that the proposed scheduling method outperforms previous list rules in terms of the calculated mean and robustness values.}, number={7}, journal={IIE TRANSACTIONS}, author={Stanfield, PM and King, RE and Hodgson, TJ}, year={2006}, month={Jul}, pages={597–607} }
 @article{taner_hodgson_king_schultz_2007, title={Satisfying due-dates in the presence of sequence dependent family setups with a special comedown structure}, volume={52}, ISSN={["0360-8352"]}, DOI={10.1016/j.cie.2006.10.008}, abstractNote={This paper addresses a static, n-job, single-machine scheduling problem with sequence dependent family setups. The setup matrix follows a special structure where a constant setup is required only if a job from a smaller indexed family is an immediate successor of one from a larger indexed family. The objective is to minimize the maximum lateness (Lmax). A two-step neighborhood search procedure and an implicit enumeration scheme are proposed. Both procedures exploit the problem structure. The enumeration scheme produces optimum solutions to small and medium sized problems in reasonable computational times, yet it fails to perform efficiently in larger instances. Computational results show that the heuristic procedure is highly effective, and is efficient even for extremely large problems.}, number={1}, journal={COMPUTERS & INDUSTRIAL ENGINEERING}, author={Taner, Mehmet R. and Hodgson, Thom J. and King, Russell E. and Schultz, Scott R.}, year={2007}, month={Feb}, pages={57–70} }
 @article{stanfield_wilson_king_2004, title={Flexible modelling of correlated operation times with application in product-reuse facilities}, volume={42}, ISSN={0020-7543 1366-588X}, url={http://dx.doi.org/10.1080/0020754042000203903}, DOI={10.1080/0020754042000203903}, abstractNote={For each job (product instance) to be serviced in a product-reuse production system, multiple operations are often scheduled. Typically, there is high variability in the same operation times required by different jobs; and for each individual job, there is often significant probabilistic dependence (correlation) between many of the job's required operation times. Well-conditioned jobs require fewer operations with shorter durations. Poorly conditioned jobs require more operations with longer durations. Accurate and rapid methods for representing the uncertainty of operation necessity and duration are required to use simulation effectively as a schedule evaluation tool. This paper develops such methods using an alternative to the conventional multivariate extension of the Johnson system of univariate probability distributions. The alternative methods match the first three, and often four, marginal moments of the random vector of operation times for a given job as well as all pairwise correlations between those operation times. A logistic regression model is used to estimate the distribution of the binary random variable indicating the necessity of an operation conditioned on the indicators for the job's preceding operations. The proposed overall mixed-distribution modelling technique is computationally efficient, useful in product-reuse system practice, and easily integrated into existing simulation software platforms.}, number={11}, journal={International Journal of Production Research}, publisher={Informa UK Limited}, author={Stanfield, P. M. and Wilson, J. R. and King, R. E.}, year={2004}, month={Jun}, pages={2179–2196} }
 @article{schultz_hodgson_king_thoney_2004, title={Minimizing L-max for large-scale, job-shop scheduling problems}, volume={42}, ISSN={["1366-588X"]}, DOI={10.1080/00207540410001721754}, abstractNote={The academic literature in 2000 presented a procedure for solving the job-shop-scheduling problem of minimizing L max. The iterative-adaptive simulation-based procedure is shown here to perform well on large-scale problems. However, there is potential for improvement in closing the gap between best-known solutions and the lower bound. In the present paper, a simulated annealing post-processing procedure is presented and evaluated on large-scale problems. A new neighbourhood structure for local searches in the job-shop scheduling problem is developed. The procedure is also evaluated using benchmark problems and new upper bounds are established.}, number={23}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, publisher={Informa UK Limited}, author={Schultz, SR and Hodgson, TJ and King, RE and Thoney, KA}, year={2004}, month={Dec}, pages={4893–4907} }
 @article{schultz_hodgson_king_taner_2004, title={Minimizing L-max for the single machine scheduling problem with family set-ups}, volume={42}, ISSN={["1366-588X"]}, DOI={10.1080/00207540410001716561}, abstractNote={A procedure for the single machine-scheduling problem of minimizing the maximum lateness for jobs with sequence independent set-ups is presented. The procedure provides optimal/near-optimal solutions over a wide range of problems. It performs well compared with other heuristics, and it is effective in finding solutions for large problems.}, number={20}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Schultz, SR and Hodgson, TJ and King, RE and Taner, MR}, year={2004}, month={Oct}, pages={4315–4330} }
 @article{wilson_king_hodgson_2004, title={Scheduling non-similar groups on a flow line: multiple group setups}, volume={20}, DOI={10.1016/j.reim.2004.07.002}, number={6}, journal={Robotics and Computer-Integrated Manufacturing}, author={Wilson, A. D. and King, Russell and Hodgson, Thom}, year={2004}, pages={505–515} }
 @article{wilson_king_hodgson_2004, title={Scheduling non-similar groups on a flow line: multiple group setups}, volume={20}, ISSN={0736-5845}, url={http://dx.doi.org/10.1016/j.rcim.2004.07.002}, DOI={10.1016/j.rcim.2004.07.002}, abstractNote={This research addresses lead-time reduction and makespan minimization for cut and sew operations of upholstered furniture manufacturing through efficient scheduling. Jobs are grouped based on different characteristics at each operation of this two stage flow line. There are identical parallel machines at each stage and jobs proceed individually from the 1st stage to the 2nd. A heuristic for the case of multiple setups per group at the 2nd stage is developed, compared to a single setup per group at each stage, and integrated into a genetic algorithm. Results demonstrate that the heuristic effectively adds minimal setups to a single setup schedule while significantly improving schedule makespan.}, number={6}, journal={Robotics and Computer-Integrated Manufacturing}, publisher={Elsevier BV}, author={Wilson, A.D. and King, R.E. and Hodgson, T.J.}, year={2004}, month={Dec}, pages={505–515} }
 @article{wilson_king_wilson_2004, title={Case study on statistically estimating minimum makespan for flow line scheduling problems}, volume={155}, ISSN={0377-2217}, url={http://dx.doi.org/10.1016/S0377-2217(02)00910-4}, DOI={10.1016/S0377-2217(02)00910-4}, abstractNote={Lower bounds are typically used to evaluate the performance of heuristics for solving combinatorial minimization problems. In the absence of tight analytical lower bounds, optimal objective-function values may be estimated statistically. In this paper, extreme value theory is used to construct confidence-interval estimates of the minimum makespan achievable when scheduling nonsimilar groups of jobs on a two-stage flow line. Experimental results based on randomly sampled solutions to each of 180 randomly generated test problems revealed that (i) least-squares parameter estimators outperformed standard analytical estimators for the Weibull approximation to the distribution of the sample minimum makespan; (ii) to evaluate each Weibull fit reliably, both the Anderson–Darling and Kolmogorov–Smirnov goodness-of-fit tests should be used; and (iii) applying a local improvement procedure to a large sample of randomly generated initial solutions improved the probability that the resulting Weibull fit yielded a confidence interval covering the minimum makespan.}, number={2}, journal={European Journal of Operational Research}, publisher={Elsevier BV}, author={Wilson, Amy D and King, Russell E and Wilson, James R}, year={2004}, month={Jun}, pages={439–454} }
 @article{zozom_hodgson_king_weintraub_cormier_2003, title={Integrated job release and shop-floor scheduling to minimize WIP and meet due-dates}, volume={41}, ISSN={["1366-588X"]}, DOI={10.1080/00207540210162992}, abstractNote={We address the problem of releasing jobs to the factory floor while meeting delivery dates and minimizing the work-in-process inventory. Heuristic algorithms were developed that used an efficient, detailed shop-floor scheduling model to determine the release times of new jobs. The process starts with the current shop floor conditions and determines the sequencing of both in-process and new jobs on machines in order to minimize the maximum lateness (L max ). The approach is tractable for industrial-sized problems and provides solutions close to a calculated lower bound for WIP. Computational experience is given.}, number={1}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Zozom, A and Hodgson, TJ and King, RE and Weintraub, AJ and Cormier, D}, year={2003}, pages={31–45} }
 @inproceedings{king_moon_1999, title={Quick response replenishment: A case study}, volume={2}, DOI={10.1109/wsc.1999.816863}, abstractNote={We document a case study based upon an ongoing analysis for a U.S. fiber/fabric manufacturer who is expanding its operations vertically to include cut and sew operations in Mexico. We refer to this vertically integrated manufacturer as VIM. While some of the data have been changed to protect the sources, the story and results themselves are unchanged. More detail on this case can be found in Moon (1999).}, booktitle={1999 Winter Simulation Conference: proceedings: Pointe Hilton Squaw Peak Resort, Phoenix, AZ, U.S.A., 5-8 December 1999}, publisher={Piscataway, New Jersey: IEEE; New York, NY: Association for Computing Machinery ; San Diego, California: Society for Computer Simulation International}, author={King, Russell and Moon, K.}, year={1999}, pages={1341–1349} }
 @article{taner_hodgson_king_thoney_2003, title={Satisfying due-dates in a job shop with sequence-dependent family set-ups}, volume={41}, ISSN={["0020-7543"]}, DOI={10.1080/0020754031000149167}, abstractNote={This paper addresses job shop scheduling with sequence dependent family set-ups. Based on a simple, single-machine dynamic scheduling problem, state dependent scheduling rules for the single machine problem are developed and tested using Markov Decision Processes. Then, a generalized scheduling policy for the job shop problem is established based on a characterization of the optimal policy. The policy is combined with a 'forecasting' mechanism to utilize global shop floor information for local dispatching decisions. Computational results show that performance is significantly better than that of existing alternative policies.}, number={17}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, publisher={Informa UK Limited}, author={Taner, MR and Hodgson, TJ and King, RE and Thoney, KA}, year={2003}, month={Nov}, pages={4153–4169} }
 @article{king_moon_nuttle_thoney_2002, title={Case Study Analysis of Inventory Stocking Policies to Support Replenishment: A Supply-chain Perspective}, volume={93}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405000208658356}, DOI={10.1080/00405000208658356}, abstractNote={Typically, in an attempt to optimize gross margin (revenue minus cost of goods), sourcing decisions for apparel products are based heavily on the lowest cost alternative. This is due to the assumption that the sourcing option does not affect the revenue side of the gross margin calculation, but it does impact the cost of goods. However, a fast, flexible supplier that can provide in-season replenishment can have a significant impact on revenue. Previous research has shown the benefit of including more than simple pre-season bottom line cost measures (e.g. King and Hunter, 1997; King and Maddalena, 1998; King et al., 1999; King, 2001). We present a case study of a manufacturer who hopes to capture the business of a major brand manufacturer who currently buys his product from a low cost, long lead time vendor. The study demonstrates the impact of in-season order replenishment, as well as the raw material inventory strategy, on the performance of a product line (program) for both the supplier and customer, as well as from a supply-chain perspective.}, number={3}, journal={Journal of the Textile Institute}, publisher={Informa UK Limited}, author={King, R. E. and Moon, W. K. and Nuttle, H. L.W and Thoney, K. A.}, year={2002}, month={Jan}, pages={25–35} }
 @article{king_brain_thoney_2002, title={Control of yarn inventory for a cotton spinning plant: part 1: Uncorrelated demand}, volume={2}, number={2}, journal={Journal of Textile and Apparel Management}, author={King, R.E. and Brain, L.A.C. and Thoney, K.A.}, year={2002} }
 @article{king_brain_thoney_2002, title={Control of yarn inventory for a cotton spinning plant: part 2: Correlated demand and seasonality}, volume={2}, number={2}, journal={Journal of Textile and Apparel Management}, author={King, R.E. and Brain, L.A.C. and Thoney, K.A.}, year={2002} }
 @article{mattila_king_ojala_2002, title={Retail performance measures for seasonal fashion}, volume={6}, ISSN={1361-2026}, url={http://dx.doi.org/10.1108/13612020210448637}, DOI={10.1108/13612020210448637}, abstractNote={Retail success can be defined as achieving high gross margins and customer service levels (i.e. being in‐stock) with as little inventory as possible. Forecast accuracy, process lead‐time, offshore/local sourcing mix and up‐front/replenishment buying mix can have a significant impact on success in connection with sourcing seasonal products with a fashion content. Forecast accuracy depends on the characteristics of the product and supply lead‐time. Lead‐times are traditionally long and buying decisions are often made seven to eight months prior to the start of the selling season. Forecast errors lead to some of the items being liquidated at clearance prices while others stockout and lead to lost sales. As a result retailers often resort to higher mark‐up prices with fashion products. However, typical retail performance measures such as service level, lost sales, product substitute percentage, gross margin, gross margin return on inventory, sell‐through percentage and mark‐down rate mask the source of the problems. In this paper, we discuss these performance measures and propose a new one. Additionally, case study analysis of a group of Finnish department stores is presented.}, number={4}, journal={Journal of Fashion Marketing and Management: An International Journal}, publisher={Emerald}, author={Mattila, Heikki and King, Russell and Ojala, Nina}, year={2002}, month={Dec}, pages={340–351} }
 @article{thoney_hodgson_king_taner_wilson_2002, title={Satisfying due-dates in large multi-factory supply chains}, volume={34}, ISSN={["1545-8830"]}, DOI={10.1080/07408170208928913}, abstractNote={A procedure is developed for the simultaneous scheduling of multi-factory supply chains, including inter-factory transportation. A job-shop scheduling procedure, known to provide near-optimal solutions to industrial-sized problems, is enhanced to include transportation elements in the fundamental model. In order to demonstrate the quality of the solutions, a lower bound calculation is compared to the procedure's solutions on a number of large-scale test problems. The lower bound is an enhancement of the classic lower bound calculation for the N-job, M-machine job shop. The computational effort in scheduling is linear in the size of the problem, and high quality solutions to large-scale problems can be obtained in seconds.}, number={9}, journal={IIE TRANSACTIONS}, publisher={Informa UK Limited}, author={Thoney, KA and Hodgson, TJ and King, RE and Taner, MR and Wilson, AD}, year={2002}, month={Sep}, pages={803–811} }
 @article{joines_kay_king_thomas culbreth_2000, title={A hybrid genetic algorithm for manufacturing cell design}, volume={17}, ISSN={1017-0669 2151-7606}, url={http://dx.doi.org/10.1080/10170669.2000.10432875}, DOI={10.1080/10170669.2000.10432875}, abstractNote={Abstract Global competition is demanding innovative ways of achieving manufacturing flexibility and reduced costs. One approach is through cellular manufacturing, an implementation of the concepts of group technology. The design of a cellular manufacturing system requires that a part population be at least minimally described by its use of process technology (padmachine incidence matrix) and partitioned into part families and that the associated plant equipment be partitioned into machine cells. At the highest level, the objective is to form a set of completely autonomous units such that inter-cell movement of parts is minimized. This paper presents a stochastic global optimization technique utilizing genetic algorithms (GAS) and local improvement procedures (LIPs) to solve the cell design problem. The combination of LIPs with GAS is shown to improve the performance of the GA in terms of solution quality and computational efficiency. Several different methods of incorporating these procedures into the GA are investigated. The concepts used in these hybrid techniques can easily be extended to other variations of the cell design problem as well as to other LIPs.}, number={5}, journal={Journal of the Chinese Institute of Industrial Engineers}, publisher={Informa UK Limited}, author={Joines, Jeffrey A. and Kay, Michael G. and King, Russell E. and Thomas Culbreth, C.}, year={2000}, month={Sep}, pages={549–564} }
 @article{joines_king_culbreth_2000, title={Moving beyond the parts incidence matrix: Alternative routings and operations for the cell formation problem}, volume={2}, journal={Journal of engineering valuation and cost analysis}, author={Joines, J.A. and King, R.E. and Culbreth, C.T.}, year={2000}, pages={327–348} }
 @article{hodgson_king_thoney_stanislaw_weintraub_zozom_1999, title={On satisfying due-dates in large job shops: Idle time insertion}, volume={32}, DOI={10.1080/07408170008963890}, abstractNote={We consider the problem of minimizing maximum lateness in a job shop. A conceptually simple simulation based procedure described in a recent paper by Hodgson et al. [1] is modified to provide improved schedules. Computational experimentation is provided to identify the conditions under which the approach is most viable, and to report the procedure's performance on known test problems.}, number={2}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Hodgson, Thom and King, Russell and Thoney, K. and Stanislaw, N. and Weintraub, A. J. and Zozom, A.}, year={1999}, pages={177–180} }
 @article{nuttle_king_hunter_wilson_fang_2000, title={Simulation Modeling of the textile supply chain - Part 1: The textile-plant models}, volume={91}, ISSN={["0040-5000"]}, DOI={10.1080/00405000008659526}, abstractNote={In Part I of the series, we describe stochastic computer models that simulate operations in the spinning, knitting, weaving, dyeing and finishing, and cut/sew sectors of the textile industry. The models are scaled to represent a supply chain designed to feed a garment-manufacturing operation involving four or five plants, i.e. part of each plant's output is ‘dedicated’ while simultaneously providing yarns and fabrics to the industry at large. Each of the sector models is unique because of the very different types of processing technology employed. The models are linked by means of streams of fabric orders from the manufacturing plants that make a range of garment types requiring many different fabrics for Basic (year-round sales), Seasonal (two or three seasons per year), and Fashion (shelf lives of 8–12 weeks) goods in a broad range of colors. In addition to each plant's product ranges and order sizes and frequencies, particular attention is paid to the machine-scheduling algorithms, although the models are deliberately kept at a ‘high’ as opposed to a ‘shop-floor’ level. The purpose of this modeling is to allow senior management to answer broad questions about the plants' ability to operate in a Quick Response environment. The various model outputs reflect this, having a heavy emphasis on on-time shipments, back-order levels, and service levels. In Part II of the series, we shall present the QR-related operating results to date, a description of a master-scheduling procedure to orchestrate the operations of the supply chain, ideas on an improved scheduling method, and an account of the construction of neural-network decision surface models as a decision support tool. We also overview ongoing efforts in technology transfer and in using ‘fuzzy’ mathematics to model the vagueness and uncertainty inherent in the supply- chain decision-making environment. The research effort of which this is a part is ongoing. We present these results in the hope of encouraging others to help carry the investigations forward.}, number={1}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Nuttle, HLW and King, RE and Hunter, NA and Wilson, JR and Fang, SC}, year={2000}, pages={35–50} }
 @article{nuttle_king_fang_wilson_hunter_2000, title={Simulation Modeling of the textile supply chain - Part II: Results and research directions}, volume={91}, ISSN={["0040-5000"]}, DOI={10.1080/00405000008659527}, abstractNote={In Part I of this series we described a set of computer-simulation models of the various components of the apparel-supply complex. Here we summarize the results obtained by exercising the models, with the main emphasis placed on whether or not the upstream operations of spinning, fabric production, and dyeing and finishing were capable of meeting Quick Response (QR) requirements for response time and service levels. In carrying out this work, questions arose about the kind of information systems required to link the various entities in the supply chain, alternative scheduling procedures, the possibility of interactive management-information systems that would allow rapid responses to the concerns of senior managers, and user-friendly means for technology transfer. We have also begun to explore the use of fuzzy mathematics to model the uncertainty and vagueness inherent in most supply-chain decision-making. Work on these topics is discussed here in Part II.}, number={1}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Nuttle, HLW and King, RE and Fang, SC and Wilson, JR and Hunter, NA}, year={2000}, pages={51–64} }
 @article{weintraub_cormier_hodgson_king_wilson_zozom_1999, title={Scheduling with alternatives: a link between process planning and scheduling}, volume={31}, DOI={10.1080/07408179908969910}, abstractNote={The objective of this research is to develop and evaluate effective, computationally efficient procedures for scheduling jobs in a large-scale manufacturing system involving, for example, over 1000 jobs and over 100 machines. The main performance measure is maximum lateness; and a useful lower bound on maximum lateness is derived from a relaxed scheduling problem in which preemption of jobs is based on the latest finish time of each job at each machine. To construct a production schedule that minimizes maximum lateness, an iterative simulation-based scheduling algorithm operates as follows: (a) job queuing times observed at each machine in the previous simulation iteration are used to compute a refined estimate of the effective due date (slack) for each job at each machine; and (b) in the current simulation iteration, jobs are dispatched at each machine in order of increasing slack. Iterations of the scheduling algorithm terminate when the lower bound on maximum lateness is achieved or the iteration limit is reached. This scheduling algorithm is implemented in Virtual Factory, a Windows-based software package. The performance of Virtual Factory is demonstrated in a suite of randomly generated test problems as well as in a large furniture manufacturing facility. To further reduce maximum lateness, a second scheduling algorithm also incorporates a tabu search procedure that identifies process plans with alternative operations and routings for jobs. This enhancement yields improved schedules that minimize manufacturing costs while satisfying job due dates. An extensive experimental performance evaluation indicates that in a broad range of industrial settings, the second scheduling algorithm can rapidly identify optimal or nearly optimal schedules.}, number={11}, journal={IIE Transactions}, author={Weintraub, A. and Cormier, D. and Hodgson, Thom and King, Russell and Wilson, J. and Zozom, A.}, year={1999}, pages={1093–1102} }
 @article{huang_culbreth_joines_king_hodgson_1998, title={Decision support system for lumber procurement and dry kiln scheduling}, volume={48}, number={9}, journal={Forest Products Journal}, author={Huang, J. C. C. and Culbreth, C. T. and Joines, J. A. and King, R. E. and Hodgson, T. J.}, year={1998}, pages={51–59} }
 @inproceedings{fang_chen_nuttle_king_1997, title={A fuzzy-control-based quick response reorder scheme for retailing of seasonal apparel}, volume={2}, booktitle={Joint Conference of Information Sciences: Semiotics, fuzzy logic, soft computing, computer vision, neural computing, genetic algorithm, pattern recognition, evolutionary computing}, publisher={Durham, NC: Duke University Machine Intelligence & Fuzzy Logic Laboratory}, author={Fang, S.-C. and Chen, T.-W. and Nuttle, H.L.W. and King, R. E.}, year={1997}, pages={300–303} }
 @article{hodgson_ge_king_said_1997, title={Dynamic lot size/sequencing policies in a multi-product, single-machine system}, volume={29}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408179708966320}, DOI={10.1080/07408179708966320}, abstractNote={This paper is concerned with the modeling and analysis of a single-machine, multi-product, integrated production–inventory system. A semi-Markov model is developed that incorporates a state-dependent control system. Control optimization is achieved through the use of Markov-renewal programming. Three- and four-product models are developed. The model(s) are exercised over a range of parameters in order to determine the characteristics of the system, and to identify the structure of the optimal control rules of the system. The result is that one can identify simple basic rules of operation that are near-optimal in a dynamic environment, and that make sense intuitively.}, number={2}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Hodgson, Thom J. and Ge, Gang and King, Russell E. and Said, Hamdy}, year={1997}, month={Feb}, pages={127–137} }
 @article{stanfield_king_hodgson_1997, title={Multiobjective stochastic scheduling of job ready times}, volume={70}, DOI={10.1023/A:1018974221508}, journal={Annals of Operations Research}, author={Stanfield, P.M. and King, R.E. and Hodgson, T.J.}, year={1997}, pages={221–239} }
 @article{hodgson_king_stanfield_1997, title={Ready-time scheduling with stochastic service times}, volume={45}, ISSN={["0030-364X"]}, DOI={10.1287/opre.45.5.779}, abstractNote={ A frequently encountered scheduling problem is to determine simultaneously a material and job ready time and production sequence based on customer-specified due dates. Each job has a stochastic production time and a deterministic due date. The ready time is constrained in that the probability that each job will be complete by its due date must meet some minimum level of confidence. The objective in such an instance is to postpone the ready time as late as possible without violating these constraints. The steps and effort necessary to determine the maximum ready time and optimal production sequence, and cases in which this effort may be significantly reduced are presented. The resulting model is applied directly to single-facility and flow-shop production environments. Methods are shown for scheduling in a dynamic environment. }, number={5}, journal={OPERATIONS RESEARCH}, author={Hodgson, TJ and King, RE and Stanfield, PM}, year={1997}, pages={779–783} }
 @article{king_hunter_1996, title={Demand Re-estimation and Inventory Replenishment of Basic Apparel in a Specialty Retail Chain}, volume={87}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405009608659100}, DOI={10.1080/00405009608659100}, abstractNote={Store replenishment and distribution center reorder systems for year-round (Basic) apparel sold through a multi-store specialty chain are described. A stochastic computer simulation model is developed which allows investigation of the effects of a wide variety of system policies on DC and store inventories, sales performance and customer service levels.}, number={1}, journal={Journal of the Textile Institute}, publisher={Informa UK Limited}, author={King, R. E. and Hunter, N. A.}, year={1996}, month={Jan}, pages={31–41} }
 @article{hunter_king_nuttle_1996, title={Evaluation of Traditional and Quick-response Retailing Procedures by Using a Stochastic Simulation Model}, volume={87}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405009608659101}, DOI={10.1080/00405009608659101}, abstractNote={A stochastic computer-simulation model is used to quantify the retail-performance characteristics of traditional and quick-response (QR) procedures for seasonal and fashion apparel. The model allows exploration of the underlying differences between the two systems, including patterns of stockout, the impact of markdowns, and buyer-forecast error, as well as the limitations on QR effectiveness imposed by season length and the number of items offered per stock-keeping unit (SKU).}, number={1}, journal={Journal of the Textile Institute}, publisher={Informa UK Limited}, author={Hunter, N. A. and King, R. E. and Nuttle, H. L.W.}, year={1996}, month={Jan}, pages={42–55} }
 @article{joines_culbreth_king_1996, title={Manufacturing cell design: an integer programming model employing genetic algorithms}, volume={28}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408179608966253}, DOI={10.1080/07408179608966253}, abstractNote={The design of a cellular manufacturing system requires that a part population, at least minimally described by its use of process technology (part/machine incidence matrix), be partitioned into part families and that the associated plant equipment be partitioned into machine cells. At the highest level, the objective is to form a set of completely autonomous units such that inter-cell movement of parts is minimized. We present an integer program that is solved using a genetic algorithm (GA) to assist in the design of cellular manufacturing systems. The formulation uses a unique representation scheme for individuals (part/machine partitions) that reduces the size of the cell formation problem and increases the scale of problems that can be solved. This approach offers improved design flexibility by allowing a variety of evaluation functions to be employed and by incorporating design constraints during cell formation. The effectiveness of the GA approach is demonstrated on several problems from the literature.}, number={1}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Joines, Jeffrey A. and Culbreth, C. Thomas and King, Russell E.}, year={1996}, month={Jan}, pages={69–85} }
 @article{houck_culbreth_king_1996, title={Neural network scheduling of a flexible manufacturing cell using dynamic process plans}, volume={4}, number={3-4}, journal={International Journal of Flexible Automation and Integrated Manufacturing}, author={Houck, C.R. and Culbreth, C.T. and King, R.E.}, year={1996}, pages={213–229} }
 @article{stanfield_king_joines_1996, title={Scheduling arrivals to a production system in a fuzzy environment}, volume={93}, ISSN={0377-2217}, url={http://dx.doi.org/10.1016/0377-2217(95)00117-4}, DOI={10.1016/0377-2217(95)00117-4}, abstractNote={A frequently encountered scheduling problem is to determine a material and job ready time while simultaneously finding a production sequence given customer-specified due dates. Often the production times and due dates are vague. This paper presents an investigation of scheduling ready times for a set of jobs with fuzzy service times and due dates. The ready time is constrained in that the possibility that a job is late must not exceed a predefined value. The objective in such an instance is to maximize the ready time without violating these constraints. The steps necessary to determine the maximum ready time and cases in which this effort may be significantly reduced are presented for single machine and flow shop production systems. Finally, a branch and bound technique is developed for cases in which the optimal job sequence cannot be determined a priori.}, number={1}, journal={European Journal of Operational Research}, publisher={Elsevier BV}, author={Stanfield, Paul M. and King, Russell E. and Joines, Jeff A.}, year={1996}, month={Aug}, pages={75–87} }
 @article{joines_king_culbreth_1995, title={A comprehensive review of manufacturing cell design}, volume={3}, number={3-4}, journal={International Journal of Flexible Automation and Integrated Manufacturing}, author={Joines, J.A. and King, R.E. and Culbreth, C.T.}, year={1995}, pages={225–264} }
 @article{king_kim_1995, title={AgvTalk: An object-oriented simulator for AGV systems}, volume={28}, ISSN={0360-8352}, url={http://dx.doi.org/10.1016/0360-8352(94)00210-e}, DOI={10.1016/0360-8352(94)00210-e}, abstractNote={In this paper, AgvTalk, an object-oriented simulation tool for the design and analysis of AGV system configuration and control is presented. Smalltalk-80 is used as an implementation language in AgvTalk. AgvTalk includes 25 object classes and more than 300 object methods in its library. Compared to general purpose simulation languages, AgvTalk provides several important benefits. First, the hierarchical features and modularity create possibilities for the extension and reuse of simulation object components. This extensibility and reusability provide more flexible modeling capabilities for simulation of many alternative AGV systems. Second, detailed behavior of each object in the AGV system can be modeled easily and exactly because there are no limiting modeling constructs. Third, AgvTalk provides a user-friendly simulation modeling environment through the MVC-triad of Smalltalk-80. This paper also presents a one-to-one comparison of modeling features between AgvTalk with traditional simulation languages.}, number={3}, journal={Computers & Industrial Engineering}, publisher={Elsevier BV}, author={King, Russell E. and Kim, Kyung Sup}, year={1995}, month={Jul}, pages={575–592} }
 @article{wu_fang_king_nuttle_1995, title={Decision surface modeling of apparel retail operations using neural network technology}, volume={1}, journal={International Journal of Operations and Quantitative Management}, author={Wu, P. and Fang, S.C. and King, R.E. and Nuttle, H.L.W.}, year={1995}, pages={33–47} }
 @article{kim_king_1995, title={Design of conventional and tandem AGV systems in an object-oriented simulation modeling environment}, volume={8}, number={1}, journal={IE Interfaces}, author={Kim, K.S. and King, R.E.}, year={1995} }
 @article{wu_fang_nuttle_wilson_king_1995, title={Guided Neural Network Learning Using a Fuzzy Controller, with Applications to Textile Spinning}, volume={2}, ISSN={0969-6016 1475-3995}, url={http://dx.doi.org/10.1111/j.1475-3995.1995.tb00020.x}, DOI={10.1111/j.1475-3995.1995.tb00020.x}, abstractNote={We apply neural networks to build a metamodel of the relation between key input parameters and output performance measures of a simulated textile spinning plant. We investigate two different neural network estimation algorithms, namely back‐propagation and an algorithm incorporating a fuzzy controller for the learning rate. According to our experience, both algorithms are capable of providing high‐quality predictions. In addition, results obtained using a fuzzy controller for the learning rate suggest a significant potential for speeding up the training process.}, number={3}, journal={International Transactions in Operational Research}, publisher={Wiley}, author={Wu, P. and Fang, S-C. and Nuttle, H.L.W. and Wilson, J.R. and King, R.E.}, year={1995}, month={Jul}, pages={259–272} }
 @article{culbreth_hopkins_king_1994, title={An object-oriented control architecture for flexible manufacturing cells: A case study}, volume={2}, number={1-2}, journal={International Journal of Flexible Automation and Integrated Manufacturing}, author={Culbreth, C.T. and Hopkins, J.M. and King, R.E.}, year={1994}, pages={95–117} }
 @article{hunter_king_nuttle_wilson_1993, title={North Carolina Apparel Pipeline Modelling Project}, volume={5}, ISSN={0955-6222}, url={http://dx.doi.org/10.1108/eb003016}, DOI={10.1108/eb003016}, abstractNote={Discusses an ongoing programme, the overall purpose of which is to develop an integrated set of stochastic simulation models of firms in the textile, apparel and retail industries. The models are to be used primarily for research, education and industrial problem solving in the areas of plant and company operations with emphasis on Quick Response (QR) methodologies driven by Point‐of‐Sale (POS) data. A second objective is that of developing interactive management information systems using high‐level decision‐surface models (simulation metamodels) of expected system performance as a function of key input parameters.}, number={3/4}, journal={International Journal of Clothing Science and Technology}, publisher={Emerald}, author={Hunter, N.A. and King, R.E. and Nuttle, H.L.W. and Wilson, J.R.}, year={1993}, month={Mar}, pages={19–24} }
 @article{king_hodgson_chafee_1993, title={ROBOT TASK SCHEDULING IN A FLEXIBLE MANUFACTURING CELL}, volume={25}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408179308964280}, DOI={10.1080/07408179308964280}, abstractNote={Effective sequencing and scheduling of the material handling system can have a major impact on the productivity of the manufacturing system. This is especially true in the case where material handling times are on par with machine processing times. In a dynamic, real-time environment, the optimal solution of this scheduling problem may be computationally infeasible. In this paper, we develop a branch and bound approach which is coupled with quick, effective bounds to optimize the movement of a robot which serves the material handling requirements within a manufacturing cell. Computational results are given which explore the tradeoff between computation time and deviation from optimal for different scenarios.}, number={2}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={King, Russell E. and Hodgson, Thom J. and Chafee, Franklin W.}, year={1993}, month={Mar}, pages={80–87} }
 @article{hunter_king_nuttle_1992, title={An Apparel-supply System for QR Retailing}, volume={83}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405009208631220}, DOI={10.1080/00405009208631220}, abstractNote={A novel apparel-supply system is described that is compatible with Quick Response retailing of apparel with a finite shelf life. The system is driven by a retail point-of-sale procedure, which regularly re-estimates customer demand and generates frequent reorders on the manufacturer and fabric supplier. The system is shown to come close to perfect supply over a range of operating conditions and thus allow greatly improved retail performance when compared with traditional retailing procedures.}, number={3}, journal={Journal of the Textile Institute}, publisher={Informa UK Limited}, author={Hunter, N. A. and King, R. E. and Nuttle, H. L.W.}, year={1992}, month={Jan}, pages={462–471} }
 @article{deleersnyder_hodgson_king_o'grady_savva_1992, title={Integrating kanban type pull systems and MRP type push systems: Insights from a Markovian model}, volume={24}, ISSN={0740-817X 1545-8830}, url={http://dx.doi.org/10.1080/07408179208964223}, DOI={10.1080/07408179208964223}, abstractNote={Approaches to multistage production scheduling can be conveniently classified into push type (i.e., Materials Requirements Planning (MRP) systems) or pull type (i.e., kanban systems). Each is generally thought to have both advantages and disadvantages. In this paper, a hybrid push/pull strategy is developed with the aim of gaining the advantages of both approaches. Material flow between work centers is regulated using the standard single card kanban/pull arrangement. Superimposed on this is the MRP-type information flow which feeds forward demand information directly to one or more (but not necessarily all) work centers. A general N-stage hybrid push/pull model is developed. The use of the approach is illustrated using 3-stage and 4-stage serial flowlines. The results indicate that the push/pull approach has lower inventory levels and a better response to demand changes than the pure pull system. The hybrid approach seems to combine many of die advantages of MRP approaches while retaining much of the simp...}, number={3}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Deleersnyder, Jean Luc and Hodgson, Thom J. and King, Russell E. and O'grady, Peter J. and Savva, Andreas}, year={1992}, month={Jul}, pages={43–56} }
 @article{nuttle_king_hunter_1991, title={A Stochastic Model of the Apparel-retailing Process for Seasonal Apparel}, volume={82}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405009508658762}, DOI={10.1080/00405009508658762}, abstractNote={A computer model is described that simulates the seasonal apparel-retailing process. The model is stochastic in nature and is designed to allow the investigation of the effects of improved retailing procedures on financial and other performance measures. Its principal value lies in the evaluation or Quick Response (QR) supply methodologies that allow frequent re-estimations of consumer demand and reorders of merchandise based on in-season point-of-sale (POS) data at the stock-keeping-unit (SKU) level.}, number={2}, journal={Journal of the Textile Institute}, publisher={Informa UK Limited}, author={Nuttle, H. L. W. and King, R. E. and Hunter, N. A.}, year={1991}, month={Jan}, pages={247–259} }
 @article{king_wilson_1991, title={A review of automated guided-vehicle systems design and scheduling}, volume={2}, ISSN={0953-7287 1366-5871}, url={http://dx.doi.org/10.1080/09537289108919329}, DOI={10.1080/09537289108919329}, abstractNote={Abstract Automated guided-vehicle (AGV) systems are gaining increasing acceptance in modern manufacturing facilities primarily because of the versatility they offer. As the flexibility and complexity of these systems increase, the requirements of the design effort and the routeing and scheduling system grow. In this paper we provide a review of the literature relevant to the system design, routeing and scheduling, and justification and implementation of AGV systems.}, number={1}, journal={Production Planning & Control}, publisher={Informa UK Limited}, author={King, Russell E. and Wilson, Carl}, year={1991}, month={Jan}, pages={44–51} }
 @article{hodgson_king_king_1991, title={Development of a production planning system: A case study}, volume={1}, number={4}, journal={Production and Inventory Management}, author={Hodgson, T.J. and King, R.E. and King, C.U.}, year={1991}, pages={18–24} }
 @article{sanii_culbreth_king_1990, title={Integrated interchangeable end of arm tooling for furniture part manipulation}, volume={1}, journal={SME Transactions}, author={Sanii, E.T. and Culbreth, C.T. and King, R.E.}, year={1990}, pages={127–153} }
 @article{culbreth_king_sanii_1989, title={A flexible manufacturing system for furniture production}, volume={2}, number={4}, journal={Manufacturing Review}, author={Culbreth, C.T. and King, R.E. and Sanii, E.T.}, year={1989}, pages={257–265} }
 @article{ding_hodgson_king_1988, title={A methodology for computation reduction for specially structured large scale Markov decision problems}, volume={34}, ISSN={0377-2217}, url={http://dx.doi.org/10.1016/0377-2217(88)90461-4}, DOI={10.1016/0377-2217(88)90461-4}, abstractNote={Markov Decision Processes (MDP's) deal with sequential decision making in stochastic systems. Existing solution techniques provide powerful tools for determining the optimal policy set in such systems. However, many problems have extremely large state and action spaces making them computationally intractable. Typically, the state variable definition is n-dimensiona and the number of states expands at a rate proportional to the power of n. For such large problems, the need for large amounts of random access memory and computation time restricts the ability to obtain solutions. The purpose of this paper is both to present a methodology which takes advantage of the structure of many large scale problems (i.e., problems with a high percentage of transient states under optimal control), and to provide computational results indicating the value of the approach.}, number={1}, journal={European Journal of Operational Research}, publisher={Elsevier BV}, author={Ding, Fong-Yuen and Hodgson, Thom J. and King, Russell E.}, year={1988}, month={Feb}, pages={105–112} }
 @article{hodgson_king_mcclave_sullivan_zegel_1987, title={Analysis and modeling of a proposed mining and beneficiation process}, volume={26}, ISSN={0888-5885 1520-5045}, url={http://dx.doi.org/10.1021/ie00071a009}, DOI={10.1021/ie00071a009}, abstractNote={Abstract : The purpose of this research was to develop an analytic model of a proposed phosphate mine which could be used to predict the quality of the water within the system throughout the useful life of the mine. The water quality is determined by tracking the concentrations of various chemical ions at key locations in the mining and beneficiation process. The results of the model were used in the evaluation of the environmental impact of a proposed mine. In this paper we will: describe the features of the proposed process; analyze the process and develop a nonstationary differential flow network model; discuss model assumptions and exogenous driving functions; compare steady-state model results with a laboratory simulation; and, finally; present dynamic modeling results. (Author)}, number={11}, journal={Industrial & Engineering Chemistry Research}, publisher={American Chemical Society (ACS)}, author={Hodgson, Thom J. and King, Russell E. and McClave, James T. and Sullivan, James H. and Zegel, William C.}, year={1987}, month={Nov}, pages={2223–2228} }
 @article{hodgson_king_monteith_schultz_1987, title={Developing control rules for an AGVS using Markov decision processes}, volume={4}, number={1}, journal={Material Flow}, author={Hodgson, T.J. and King, R.E. and Monteith, S.K. and Schultz, S.R.}, year={1987}, pages={87–98} }
 @article{king_hodgson_monteith_1987, title={Extracting heuristic control rules for AGV's using Markov decision processes}, volume={27}, number={2}, journal={Belgian Journal of Operations Research, Statistics and Computer Science}, author={King, R.E. and Hodgson, T.J. and Monteith, S.K.}, year={1987}, pages={3–17} }