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Author Alvarez-Miranda, E.; Chace, S.; Pereira, J.
Title Assembly line balancing with parallel workstations Type
Year 2021 Publication International Journal Of Production Research Abbreviated Journal Int. J. Prod. Res.
Volume 59 Issue 21 Pages 6486-6506
Keywords Line balancing; parallel stations; dynamic programming; hybrid metaheuristic; matheuristic
Abstract The simple assembly line balancing problem (SALBP) considers work division among different workstations of a serially arranged assembly process to maximise its efficiency under workload (cumulative) and technological (precedence) constraints. In this work, we consider a variant of the SALBP which allows parallel workstations. To study the effect of parallel stations, we propose a new problem (the parallel station assembly line balancing problem or PSALBP) in which the objective is to minimise the number of parallel stations required to obtain the maximum theoretical efficiency of the assembly process. We study the complexity of the problem and identify a polynomially solvable case. This result is then used as a building block for the development of a heuristic solution procedure. Finally, we carry out a computational experiment to identify the characteristics of assembly lines that may benefit from station paralleling and to evaluate the performance of the proposed heuristic.
Address [alvarez-Miranda, Eduardo] Univ Talca, Fac Engn, Dept Ind Engn, Curico, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Taylor & Francis Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-7543 ISBN Medium
Area Expedition Conference
Notes WOS:000569837900001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1243
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Author Bitran, G.; Mondschein, S.
Title Why individualized contact policies are critical in the mass affluent market Type
Year 2015 Publication Academia-Revista Latinoamericana De Administracion Abbreviated Journal Acad.-Rev. Latinoam. Adm.
Volume 28 Issue 2 Pages 251-272
Keywords Marketing and advertising; Stochastic dynamic programming
Abstract Purpose – The purpose of this paper is to study the optimal contact policies for customers that belong to the mass affluent market. Design/methodology/approach – The authors formulate a stochastic dynamic programming model to determine the optimal frequency of contacts in order to maximize the expected return of the company. Findings – The authors show that personalized marketing strategies provide a competitive advantage to companies that contact their customers directly through, for example, phone calls or meetings. The authors show that a threshold policy is only optimal for customers with increasing sensitivity to contact. In all other cases, optimal policies might have a less intuitive structure. The authors also study the importance of the size of the customer database and determine the optimal maximum recency when maintenance costs are present. Practical implications – Contact policies should be tailored for each company/industry individually, due to their sensitivity to customers' purchasing behavior.
Address [Bitran, Gabriel] MIT, Sloan Sch Business, Cambridge, MA 02139 USA, Email: susana.mondschein@uai.cl
Corporate Author Thesis
Publisher Emerald Group Publishing Limited Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1012-8255 ISBN Medium
Area Expedition Conference
Notes WOS:000357386800006 Approved
Call Number UAI @ eduardo.moreno @ Serial 511
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Author Mondschein, S.; Yankovic, N.; Matus, O.
Title Age-dependent optimal policies for hepatitis C virus treatment Type
Year 2021 Publication International Transactions In Operational Research Abbreviated Journal Int. Trans. Oper. Res.
Volume 28 Issue 6 Pages 3303-3329
Keywords dynamic programming; public health; hepatitis C virus
Abstract In recent years, highly effective treatments for hepatitis C virus (HCV) have become available. However, high prices of new treatments call for a careful policy evaluation when considering economic constraints. Although the current medical advice is to administer the new therapies to all patients, economic and capacity constraints require an efficient allocation of these scarce resources. We use stochastic dynamic programming to determine the optimal policy for prescribing the new treatment based on the age and disease progression of the patient. We show that, in a simplified version of the model, new drugs should be administered to patients at a given level of fibrosis if they are within prespecified age limits; otherwise, a conservative approach of closely monitoring the evolution of the patient should be followed. We use a cohort of Spanish patients to study the optimal policy regarding costs and health indicators. For this purpose, we compare the performance of the optimal policy against a liberal policy of treating all sick patients. In this analysis, we achieve similar results in terms of the number of transplants, HCV-related deaths, and quality of adjusted life years, with a significant reduction in overall expenditure. Furthermore, the budget required during the first year of implementation when using the proposed methodology is only 12% of that when administering the treatment to all patients at once. Finally, we propose a method to prioritize patients when there is a shortage (surplus) in the annual budget constraint and, therefore, some recommended treatments must be postponed (added).
Address [Mondschein, Susana; Matus, Omar] Univ Adolfo Ibanez, Fac Ingn, Diagonal Las Torres 2640, Santiago 755000, Chile, Email: susana.mondschein@uai.cl;
Corporate Author Thesis
Publisher Wiley Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0969-6016 ISBN Medium
Area Expedition Conference
Notes WOS:000481229600001 Approved
Call Number UAI @ eduardo.moreno @ Serial 1041
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Author Pereira, J.
Title Procedures for the bin packing problem with precedence constraints Type
Year 2016 Publication European Journal Of Operational Research Abbreviated Journal Eur. J. Oper. Res.
Volume 250 Issue 3 Pages 794-806
Keywords Bin packing; Precedence constraints; Lower bounds; Dynamic programming; Branch-and-bound
Abstract The bin packing problem with precedence constraints (BPP-P) is a recently proposed variation of the classical bin packing problem (BPP), which corresponds to a basic model featuring many underlying characteristics of several scheduling and assembly line balancing problems. The formulation builds upon the BPP by incorporating precedence constraints among items, which force successor items to be packed into later bins than their predecessors. In this paper we propose a dynamic programming based heuristic, and a modified exact enumeration procedure to solve the problem. These methods make use of several new lower bounds and dominance rules tailored for the problem in hand. The results of a computational experiment show the effectiveness of the proposed methods, which are able to close all of the previous open instances from the benchmark instance set within very reduced running times. (C) 2015 Elsevier B.V. and Association of European Operational Research Societies (EURO) within the International Federation of Operational Research Societies (IFORS). All rights reserved.
Address [Pereira, Jordi] Univ Adolfo Ibanez, Fac Sci & Engn, Ave Padre Hurtado 750,Off C216, Vina Del Mar, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0377-2217 ISBN Medium
Area Expedition Conference
Notes WOS:000369192500011 Approved
Call Number UAI @ eduardo.moreno @ Serial 581
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Author Pereira, J.; Ritt, M
Title A note on “Algorithms for the Calzedonia workload allocation problem” Type
Year 2022 Publication Journal of the Operational Research Society Abbreviated Journal J. Oper. Res. Soc.
Volume 73 Issue 6 Pages 1420-1422
Keywords Assembly line balancing; worker allocation; dynamic programming
Abstract Battarra et al. recently proposed a novel assembly line balancing problem with applications to the apparel industry, where the tasks are performed in a fixed order. To solve the problem, one has to assign workers and tasks to the workstations with the objective of maximising the throughput of the assembly line. In this paper, we provide dynamic programming formulations for the general problem and some special cases. We then use these formulations to develop an exact solution approach that optimally solves the instances in Battarra et al. within seconds.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0160-5682 ISBN Medium
Area Expedition Conference
Notes WOS:000627308200001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1351
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Author Reus, L.; Pagnoncelli, B.; Armstrong, M.
Title Better management of production incidents in mining using multistage stochastic optimization Type
Year 2019 Publication Resources Policy Abbreviated Journal Resour. Policy
Volume 63 Issue Pages 13 pp
Keywords Mining incidents; Optimal policy; Stochastic dual dynamic programming; Risk-aversion; CVaR; Julia language
Abstract Among the many sources of uncertainty in mining are production incidents: these can be strikes, environmental issues, accidents, or any kind of event that disrupts production. In this work, we present a strategic mine planning model that takes into account these types of incidents, as well as random prices. When confronted by production difficulties, mines which have contracts to supply customers have a range of flexibility options including buying on the spot market, or taking material from a stockpile if they have one. Earlier work on this subject was limited in that the optimization could only be carried out for a few stages (up to 5 years) and in that it only analyzed the risk-neutral case. By using decomposition schemes, we are now able to solve large-scale versions of the model efficiently, with a horizon of up to 15 years. We consider decision trees with up to 615 scenarios and implement risk aversion using Conditional Value-at-Risk, thereby detecting its effect on the optimal policy. The results provide a “roadmap” for mine management as to optimal decisions, taking future possibilities into account. We present extensive numerical results using the new sddp.jl library, written in the Julia language, and discuss policy implications of our findings.
Address [Reus, Lorenzo] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: lorenzo.reus@uai.cl;
Corporate Author Thesis
Publisher Elsevier Sci Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0301-4207 ISBN Medium
Area Expedition Conference
Notes WOS:000488888100004 Approved
Call Number UAI @ eduardo.moreno @ Serial 1165
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