@article{slocum_jones_fletcher_mcconnell_hodgson_taheri_wilson_2020, title={Improving chemotherapy infusion operations through the simulation of scheduling heuristics: a case study}, volume={2}, ISSN={2047-6965 2047-6973}, url={http://dx.doi.org/10.1080/20476965.2019.1709908}, DOI={10.1080/20476965.2019.1709908}, abstractNote={ABSTRACT Over the last decade, chemotherapy treatments have dramatically shifted to outpatient services such that nearly 90% of all infusions are now administered outpatient. This shift has challenged oncology clinics to make chemotherapy treatment as widely available as possible while attempting to treat all patients within a fixed period of time. Historical data from a Veterans Affairs chemotherapy clinic in the United States and staff input informed a discrete event simulation model of the clinic. The case study examines the impact of altering the current schedule, where all patients arrive at 8:00 AM, to a schedule that assigns patients to two or three different appointment times based on the expected length of their chemotherapy infusion. The results identify multiple scheduling policies that could be easily implemented with the best solutions reducing both average patient waiting time and average nurse overtime requirements.}, journal={Health Systems}, publisher={Informa UK Limited}, author={Slocum, Ryan F. and Jones, Herbert L. and Fletcher, Matthew T. and McConnell, Brandon M. and Hodgson, Thom J. and Taheri, Javad and Wilson, James R.}, year={2020}, month={Feb}, pages={1–16} } @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{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{karagul_warsing_hodgson_kapadia_uzsoy_2018, title={A comparison of mixed integer programming formulations of the capacitated lot-sizing problem}, volume={56}, ISSN={["1366-588X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85035114913&partnerID=MN8TOARS}, DOI={10.1080/00207543.2017.1401232}, abstractNote={We propose a novel mixed integer programming formulation for the capacitated lot-sizing problem with set-up times and set-up carryover. We compare our formulation to two earlier formulations, the Classical and Modified formulations, and a more recent formulation due to Suerie and Stadtler. Extensive computational experiments show that our formulation consistently outperforms the Classical and Modified formulations in terms of CPU time and solution quality. It is competitive with the Suerie–Stadtler (S&S) formulation, but outperforms all other formulations on the most challenging instances, those with low-capacity slack and a dense jobs matrix. We show that some of the differences in the performance of these various formulations arise from their different use of binary variables to represent production or set-up states. We also show that the LP relaxation of our Novel formulation provides a tighter lower bound than that of the Modified formulation. Our experiments demonstrate that, while the S&S formulation provides a much tighter LP bound, the Novel formulation is better able to exploit the intelligence of the CPLEX solution engine.}, number={23}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Karagul, Hakan F. and Warsing, Donald P. and Hodgson, Thom J. and Kapadia, Maaz S. and Uzsoy, Reha}, year={2018}, pages={7064–7084} } @article{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{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{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{lobo_hodgson_king_thoney_wilson_2013, title={Allocating job-shop manpower to minimize : 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{lobo_hodgson_king_thoney_wilson_2013, title={An effective lower bound on Lmax 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{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{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{laoboonlur_hodgson_thoney_2006, title={Production scheduling in a knitted fabric dyeing and finishing process}, volume={97}, DOI={10.1533/joti.2005.0145}, number={5}, journal={Journal of the Textile Institute}, author={Laoboonlur, P. and Hodgson, Thom and Thoney, K. A.}, year={2006}, pages={391–399} } @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{hodgson_jackson_qu_cannon_2004, title={A material allocation scheme for optical fibre cable manufacturing: a case study}, volume={42}, ISSN={["0020-7543"]}, DOI={10.1080/00207540410001688400}, abstractNote={Optical fibre cable manufacturing is a multistep process that combines individual fibres into colour-coded buffer tubes. These tubes are grouped together to make cables in which individual fibres are protected from external loads and environmental factors. This assembly process has a tree structure in which components are progressively combined into a finished cable. The main component, optical fibre, is held in inventory on spools in varying lengths and in both pre-coloured and natural states. Orders are received for lengths of finished cable. Since the glass fibre is the highest cost component of the cable, the allocation of fibre inventory to orders should be accomplished so that fibre scrap is minimized. In this paper a heuristic procedure for minimizing glass fibre scrap is presented. Computational results are given.}, number={16}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Hodgson, TJ and Jackson, SD and Qu, P and Cannon, RE}, year={2004}, month={Aug}, pages={3271–3279} } @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, R. E. 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{hodgson_melendez_trainor_2004, title={The deployment scheduling analysis tool (DSAT)}, volume={39}, DOI={10.1016/j.mcm.2004.02.021}, number={08-Jun}, journal={Mathematical and Computer Modelling}, author={Hodgson, Thom and Melendez, B. and Trainor, T.}, year={2004}, pages={905–924} } @article{hodgson_melendez_thoney_trainor_2004, place={San Diego}, title={The deployment scheduling analysis tool (DSAT)}, volume={39}, ISSN={0895-7177}, url={http://dx.doi.org/10.1016/s0895-7177(04)90561-4}, DOI={10.1016/s0895-7177(04)90561-4}, abstractNote={The deployment scheduling analysis tool is an analysis tool for studying military deployment scenarios. The tool has a user interface through which the user selects the deploying units, equipment, and their required delivery dates. The user also selects the ports (air, rail, and sea) through which the units will travel to get to the final destination. Finally, the user selects the transportation assets on which the units will travel and assigns those assets to the routes in the deployment network. The system schedules the equipment for deployment by creating individual equipment routings and then repetitively simulating the deployment to determine the deployment closure time and the maximum lateness (Lmax) of any unit. The equipment is scheduled to minimize the maximum lateness of all deploying units. Deployment information is formatted into various graphs and reports. Finally, the user can modify various aspects of the deployment scenario to conduct sensitivity analysis. A valuable option is a heuristic procedure to reassign transportation assets in an attempt to further reduce the deployment closure time and Lmax.}, number={6-8}, journal={Mathematical and Computer Modelling}, publisher={Elsevier BV}, author={Hodgson, T.J and Melendez, B and Thoney, K.A and Trainor, T}, editor={Brigantic, R.T. and Mahan, J.M.Editors}, year={2004}, month={Mar}, pages={905–924} } @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} } @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{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{yaghubian_hodgson_joines_2001, title={Dry-or-buy decision support for dry kiln scheduling in furniture production}, volume={33}, url={https://doi.org/10.1023%2Fa%3A1007603002606}, DOI={10.1023/A:1007603002606}, abstractNote={In this paper, a dry-or-buy cost model for a dry kiln scheduling problem in the furniture manufacturing industry is considered. Factory-specified due-dates for jobs, kiln availability, kiln capacity, and drying and buying costs are incorporated into an Integer-Programming (IP) model. As it may be difficult (i.e., because of due-dates, kiln availability, processing times, etc.) to meet all the due-dates, certain jobs may have to be out-sourced. The objective of the model is to minimize the total drying and buying costs while satisfying all due-dates. Because of the computational complexity of the problem, a heuristic approach is developed. Computational experience indicates that the heuristic gives high quality solutions with significant savings in time over standard IP algorithms.}, number={2}, journal={IIE Transactions}, publisher={Springer Nature}, author={Yaghubian, A. R. and Hodgson, T. J. and Joines, J. A.}, year={2001}, pages={131–136} } @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, R. E. and Thoney, K. and Stanislaw, N. and Weintraub, A. J. and Zozom, A.}, year={1999}, pages={177–180} } @article{yaghubian_hodgson_joines_culbreth_huang_1999, title={Dry kiln scheduling in furniture production}, volume={31}, DOI={10.1080/07408179908969872}, abstractNote={In this paper, a dry kiln scheduling problem from the furniture manufacturing industry is considered. Factory-specified due dates for orders, kiln availability, kiln capacity, and travel time from the kilns to the factories are all incorporated in a model which is formulated as an integer linear program. The objective of the formulation is to minimize the maximum tardiness of orders arriving at the plants by solving a special case of scheduling n independent jobs on m non-identical parallel ciachines. Because of the computational complexity, and the fact that standard integer programming packages appear to perform very poorly on the problem, a heuristic approach is developed. Computational experience is provided which indicates that the heuristic gives very high quality solutions to problems in near real-time.}, number={8}, journal={IIE Transactions}, publisher={Informa UK Limited}, author={Yaghubian, A. R. and Hodgson, T. J. and Joines, J. A. and Culbreth, C. T. and Huang, J. C.}, year={1999}, pages={733–738} } @article{hodgson_kay_mittal_tang_1999, title={Evaluation of cylindricity using combinatorics}, volume={31}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85023862738&partnerID=MN8TOARS}, DOI={10.1080/07408179908969804}, abstractNote={Several numerical methods have been developed for finding the minimum zone of a cylinder. This paper presents a combinatorial method termed the Minimum Shell for cylindricity evaluation. For a given set of measured data points, the method efficiently searches for the six points that determine the minimum zone of cylindricity. This method is self-contained, without the requirement of mathematical programming software support, and is equal to or superior to other methods of evaluating cylindricity in terms of accuracy, efficiency, and simplicity. Computational results are given.}, number={1}, journal={IIE Transactions}, author={Hodgson, Thom and Kay, M. G. and Mittal, R. O. and Tang, S. Y.}, year={1999}, pages={39–47} } @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, R. and Wilson, J. and Zozom, A.}, year={1999}, pages={1093–1102} } @article{wang_fang_hodgson_1998, title={A fuzzy due-date bargainer for the make-to-order manufacturing systems}, volume={28}, ISSN={["1558-2442"]}, DOI={10.1109/5326.704596}, abstractNote={For a make-to-order manufacturing system, the uncertainty and flexibility of the due dates required by customers and the production capacity owned by the manufacturer can be modeled in a fuzzy environment. A combined due-date assignment and production planning methodology for the make-to-order manufacturing systems is developed. The fuzzy approach determines the optimal due dates for the manufacturer based upon a "rough-cut" resource balance, while a customer can request earlier due dates by paying a higher price to cover the extra manufacturing cost incurred. The resulting fuzzy due-date bargainer is exercised using manufacturing resource planning (MRP-II) data from a furniture manufacturing company. Experimental results indicate its potential as a useful tool for real applications.}, number={3}, journal={IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART C-APPLICATIONS AND REVIEWS}, author={Wang, DW and Fang, SC and Hodgson, TJ}, year={1998}, month={Aug}, pages={492–497} } @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} } @article{hodgson_cormier_weintraub_zozom_1998, title={Note. Satisfying due dates in large job shops}, volume={44}, ISSN={["0025-1909"]}, DOI={10.1287/mnsc.44.10.1442}, abstractNote={ For the multi-machine job shop scheduling problem, a conceptually simple simulation-based procedure (first proposed by Lawrence and Morton 1986) is shown to be both effective and efficient in providing optimal, or near optimal, schedules for minimizing the maximum lateness, Lmax. Computational experimentation is used to identify the conditions under which the approach is most viable. }, number={10}, journal={MANAGEMENT SCIENCE}, author={Hodgson, TJ and Cormier, D and Weintraub, AJ and Zozom, A}, year={1998}, month={Oct}, pages={1442–1446} } @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} }