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16
Facility Location under Uncertainty: A Review
 IIE Transactions
, 2004
"... Plants, distribution centers, and other facilities generally function for years or decades, during which time the environment in which they operate may change substantially. Costs, demands, travel times, and other inputs to classical facility location models may be highly uncertain. This has made th ..."
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Cited by 77 (7 self)
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Plants, distribution centers, and other facilities generally function for years or decades, during which time the environment in which they operate may change substantially. Costs, demands, travel times, and other inputs to classical facility location models may be highly uncertain. This has made the development of models for facility location under uncertainty a high priority for researchers in both the logistics and stochastic/robust optimization communities. Indeed, a large number of the approaches that have been proposed for optimization under uncertainty have been applied to facility location problems. This paper reviews the literature...
Stochastic pRobust Location Problems
, 2004
"... Many objectives have been proposed for optimization under uncertainty. The typical stochastic programming objective of minimizing expected cost may yield solutions that are inexpensive in the long run but perform poorly under certain realizations of the random data. On the other hand, the typical ro ..."
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Cited by 22 (4 self)
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Many objectives have been proposed for optimization under uncertainty. The typical stochastic programming objective of minimizing expected cost may yield solutions that are inexpensive in the long run but perform poorly under certain realizations of the random data. On the other hand, the typical robust optimization objective of minimizing maximum cost or regret tends to be overly conservative, planning against a disastrous but unlikely scenario. In this paper, we present facility location models that combine the two objectives by minimizing the expected cost while bounding the relative regret in each scenario. In particular, the models seek the minimumexpectedcost solution that is probust; i.e., whose relative regret is no more than 100p% in each scenario.
Facility Location: A Robust Optimization Approach
"... I n this research, we apply robust optimization (RO) to the problem of locating facilities in a network facing uncertaindemand over multiple periods. We consider a multiperiod fixedcharge network location problem for which we find (1) the number of facilities, their location and capacities, (2) th ..."
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Cited by 3 (1 self)
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I n this research, we apply robust optimization (RO) to the problem of locating facilities in a network facing uncertaindemand over multiple periods. We consider a multiperiod fixedcharge network location problem for which we find (1) the number of facilities, their location and capacities, (2) the production in each period, and (3) allocation of demand to facilities. Using the RO approach we formulate the problem to include alternate levels of uncertainty over the periods. We consider two models of demand uncertainty: demand within a bounded and symmetric multidimensional box, and demand within a multidimensional ellipsoid. We evaluate the potential benefits of applying the RO approach in our setting using an extensive numerical study. We show that the alternate models of uncertainty lead to very different solution network topologies, with the model with box uncertainty set opening fewer, larger facilities. Through sample path testing, we show that both the box and ellipsoidal uncertainty cases can provide small but significant improvements over the solution to the problem when demand is deterministic and set at its nominal value. For changes in several environmental parameters, we explore the effects on the solution performance. Key words: facility location; robust optimization; uncertainty; robust counterpart
Robust algorithm for the uncertain scheduling problem with moving executors
 In Proc. of 16th IFAC World Congress, Prague, 2005 [cdrom]. i ∈ 1 = wi i 2 = 1 ≈ * < 2
"... Abstract: In the paper the combined routingscheduling problem which consists in scheduling of tasks on moving executors is considered. The case with nonpreemptive and independent tasks, unrelated executors as well as interval processing times to minimize the maximum lateness is investigated. The r ..."
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Cited by 1 (1 self)
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Abstract: In the paper the combined routingscheduling problem which consists in scheduling of tasks on moving executors is considered. The case with nonpreemptive and independent tasks, unrelated executors as well as interval processing times to minimize the maximum lateness is investigated. The robust scheduling problem based on the modified relative regret function is formulated. The solution algorithm uses the result which allows to reduce an uncertain problem to a number of deterministic problems. Then the uncertain problem considered can be solved by a deterministic algorithm. The simple numerical example is given. Copyright © 2005 IFAC
Challenges in the Global Supply Chain: Exploitation versus Exploration Strategy,” Unpublished
, 2010
"... entitled ..."
Theory and Methodology A heuristic to minimax absolute regret for linear programs with interval objective function coecients
"... Abstract Decision makers faced with uncertain information often experience regret upon learning that an alternative action would have been preferable to the one actually selected. Models that minimize the maximum regret can be useful in such situations, especially when decisions are subject to ex p ..."
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Abstract Decision makers faced with uncertain information often experience regret upon learning that an alternative action would have been preferable to the one actually selected. Models that minimize the maximum regret can be useful in such situations, especially when decisions are subject to ex post review. Of particular interest are those decision problems that can be modeled as linear programs with interval objective function coecients. The minimax regret solution for these formulations can be found using an algorithm that, at each iteration, solves ®rst a linear program to obtain a candidate solution and then a mixed integer program (MIP) to maximize the corresponding regret. The exact solution of the MIP is computationally expensive and becomes impractical as the problem size increases. In this paper, we develop a heuristic for the MIP and investigate its performance both alone and in combination with exact procedures. The heuristic is shown to be eective for problems that are signi®cantly larger than those previously reported in the literature. Ó
Pricing decisions in a twoechelon decentralized supply chain using bilevel programming approach
, 2015
"... Abstract Pricing is one of the major aspects of decision making in supply chain. In the previous works mostly a centralized environment is considered indicating the retailers cannot independently apply their decisions on the pricing strategy. Although in a twoechelon decentralized environment it m ..."
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Abstract Pricing is one of the major aspects of decision making in supply chain. In the previous works mostly a centralized environment is considered indicating the retailers cannot independently apply their decisions on the pricing strategy. Although in a twoechelon decentralized environment it may be possible that supply chain contributors have encountered with different market power situations which provide that some of them try to impose their interests in pricing and/or volume of the products. In such situations the leaderfollower Stackelberg game or more specifically bilevel programming seems to be the best approach to overcome the problem. Furthermore, in this study we consider the impacts of disruption risk caused by foreign exchange uncertainty on pricing decisions in a multiproduct twoechelon supply chain. Also it is assumed that the market is partitioned to domestic and international retailers with segmented market for each retailer. The purpose of this paper is to introduce decisions policy on the pricing such that the utility of both manufacturer and retailers is met. Since the proposed bilevel model is NPhard, a simulated annealing method combining with Tabu search is proposed to solve the model. A numerical example is presented to investigate the effect of foreign exchange variation on the decision variables through different scenarios. The results from numerical example indicate that the international retailers are indifferent to the manufacture undergoes changes where the domestic retailers react to changes, dramatically.
Uncertain Supply Chain Management A Probust model in humanitarian logistics in a nonneutral political environment
, 2016
"... Humanitarian assistance by foreign organizations in general and foreign military forces in particular, is typically provided in a nonneutral political environment. Local politics that range from national pride, through strained relations with the country offering military logistic support, to blat ..."
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Humanitarian assistance by foreign organizations in general and foreign military forces in particular, is typically provided in a nonneutral political environment. Local politics that range from national pride, through strained relations with the country offering military logistic support, to blatant aversion to the population in need, affect the ability to provide effective humanitarian aid. The current paper presents the use of mathematical modeling and robustness approach when the government of the affected area declines offers of aid from international organizations because of political constraints. The multiobjective model seeks to minimize unsatisfied demands and total costs of the government and suppliers. To explore the effects of various parameters and show managerial insights that can guide DMs under a variety of conditions, the sensitivity analysis of the experiments are presented.