2018 |
Tellez, Oscar; Vercraene, Samuel; Lehuédé, Fabien; Péton, Olivier; Monteiro, Thibaud The fleet size and mix dial-a-ride problem with reconfigurable vehicle capacity Journal Article Transportation Research Part C: Emerging Technologies, 91 , pp. 99-123, 2018. @article{tellez:hal-01619103, title = {The fleet size and mix dial-a-ride problem with reconfigurable vehicle capacity}, author = {Oscar Tellez and Samuel Vercraene and Fabien Lehu\'{e}d\'{e} and Olivier P\'{e}ton and Thibaud Monteiro}, url = {https://hal.archives-ouvertes.fr/hal-01619103}, doi = {10.1016/j.trc.2018.03.020}, year = {2018}, date = {2018-06-01}, journal = {Transportation Research Part C: Emerging Technologies}, volume = {91}, pages = {99-123}, institution = {Laboratoire DISP}, abstract = {This paper introduces a fleet size and mix dial-a-ride problem with multiple passenger types and a heterogeneous fleet of reconfigurable vehicles. In this new variant of the dial-a-ride problem, en-route modifications of the vehicle’s inner configuration are allowed. The main consequence is that the vehicle capacity is defined by a set of configurations and the choice of vehicle configuration is associated with binary decision variables. The problem is modeled as a mixed-integer program derived from the model of the heterogeneous dial-a-ride problem. Vehicle reconfiguration is a lever to efficiently reduce transportation costs, but the number of passengers and vehicle fleet setting make this problem intractable for exact solution methods. A large neighborhood search metaheuristic combined with a set covering component with a reactive mechanism to automatically adjust its parameters is therefore proposed. The resulting framework is evaluated against benchmarks from the literature, used for similar routing problems. It is also applied to a real case, in the context of the transportation of disabled children from their home to medical centers in the city of Lyon, France. }, type = {Thechnical report}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper introduces a fleet size and mix dial-a-ride problem with multiple passenger types and a heterogeneous fleet of reconfigurable vehicles. In this new variant of the dial-a-ride problem, en-route modifications of the vehicle’s inner configuration are allowed. The main consequence is that the vehicle capacity is defined by a set of configurations and the choice of vehicle configuration is associated with binary decision variables. The problem is modeled as a mixed-integer program derived from the model of the heterogeneous dial-a-ride problem. Vehicle reconfiguration is a lever to efficiently reduce transportation costs, but the number of passengers and vehicle fleet setting make this problem intractable for exact solution methods. A large neighborhood search metaheuristic combined with a set covering component with a reactive mechanism to automatically adjust its parameters is therefore proposed. The resulting framework is evaluated against benchmarks from the literature, used for similar routing problems. It is also applied to a real case, in the context of the transportation of disabled children from their home to medical centers in the city of Lyon, France. |
2017 |
Gayon, Jean-Philippe; Vercraene, Samuel; Flapper, Simme Douwe P Optimal control of a production-inventory system with product returns and two disposal options Journal Article European Journal of Operational Research, 262 (2), pp. 499–508, 2017, ISSN: 0377-2217. @article{gayon_optimal_2017, title = {Optimal control of a production-inventory system with product returns and two disposal options}, author = {Jean-Philippe Gayon and Samuel Vercraene and Simme Douwe P Flapper}, url = {https://pdfs.semanticscholar.org/56d0/71c824ed759553f37078ba3570561a235af1.pdf}, doi = {10.1016/j.ejor.2017.03.018}, issn = {0377-2217}, year = {2017}, date = {2017-10-16}, urldate = {2017-06-15}, journal = {European Journal of Operational Research}, volume = {262}, number = {2}, pages = {499--508}, abstract = {We consider a production-inventory system facing stochastic product returns that can either be disposed upon arrival or placed in a serviceable inventory, where serviceable products can be disposed at any time. In an M/M/1 make-to-stock queue setting, we establish that the optimal control policy is a threshold policy with three policy parameters and we derive closed-form results for the optimal thresholds and costs. For several situations, we establish that either the disposal upon arrival (DUA) option or the disposal of serviceable products (SD) option is sufficient to achieve optimality. We also present numerical examples for which it is useful to have both disposal options. Moreover, we explore four extensions for which the two options are complementary (limited secondary market, manufacturing start-up cost, Markov modulated demand and positive remanufacturing lead time).}, keywords = {}, pubstate = {published}, tppubtype = {article} } We consider a production-inventory system facing stochastic product returns that can either be disposed upon arrival or placed in a serviceable inventory, where serviceable products can be disposed at any time. In an M/M/1 make-to-stock queue setting, we establish that the optimal control policy is a threshold policy with three policy parameters and we derive closed-form results for the optimal thresholds and costs. For several situations, we establish that either the disposal upon arrival (DUA) option or the disposal of serviceable products (SD) option is sufficient to achieve optimality. We also present numerical examples for which it is useful to have both disposal options. Moreover, we explore four extensions for which the two options are complementary (limited secondary market, manufacturing start-up cost, Markov modulated demand and positive remanufacturing lead time). |
Vercraene, Samuel; Gayon, Jean-Philippe; Karaesmen, Fikri Effects of System Parameters on the Optimal Cost and Policy in a Class of Multidimensional Queueing Control Problems Journal Article Operations Research, 66 (1), pp. 150 - 162, 2017, ISSN: 0030-364X. @article{vercraene_effects_2017, title = {Effects of System Parameters on the Optimal Cost and Policy in a Class of Multidimensional Queueing Control Problems}, author = {Samuel Vercraene and Jean-Philippe Gayon and Fikri Karaesmen}, url = {http://home.ku.edu.tr/~fkaraesmen/pdfpapers/VGK_sensitivity_2015.pdf}, doi = {10.1287/opre.2017.1600}, issn = {0030-364X}, year = {2017}, date = {2017-06-14}, urldate = {2017-06-15}, journal = {Operations Research}, volume = {66}, number = {1}, pages = {150 - 162}, abstract = {We consider a class of Markov Decision Processes frequently employed to model queueing and inventory control problems. For these problems, we explore how changes in different system input parameters (transition rates, costs, discount rates etc.) affect the optimal cost and the optimal policy when the state space of the problem is multidimensional. To address a large class of problems, we introduce two generic dynamic programming operators to model different types of controlled events. For these operators, we derive sufficient conditions to propagate monotonicity and supermodularity properties of the value function. These properties allow to predict how changes in system input parameters affect the optimal cost and policy. Finally, we explore the case when several parameters are changed at the same time.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We consider a class of Markov Decision Processes frequently employed to model queueing and inventory control problems. For these problems, we explore how changes in different system input parameters (transition rates, costs, discount rates etc.) affect the optimal cost and the optimal policy when the state space of the problem is multidimensional. To address a large class of problems, we introduce two generic dynamic programming operators to model different types of controlled events. For these operators, we derive sufficient conditions to propagate monotonicity and supermodularity properties of the value function. These properties allow to predict how changes in system input parameters affect the optimal cost and policy. Finally, we explore the case when several parameters are changed at the same time. |
2014 |
Vercraene, Samuel; Gayon, Jean-Philippe; Flapper, Simme Douwe P Coordination of manufacturing, remanufacturing and returns acceptance in hybrid manufacturing/remanufacturing systems Journal Article International Journal of Production Economics, 148 , pp. 62–70, 2014, ISSN: 0925-5273. @article{vercraene_coordination_2014, title = {Coordination of manufacturing, remanufacturing and returns acceptance in hybrid manufacturing/remanufacturing systems}, author = {Samuel Vercraene and Jean-Philippe Gayon and Simme Douwe P Flapper}, url = {http://purl.tue.nl/940711707960726.pdf}, doi = {10.1016/j.ijpe.2013.11.001}, issn = {0925-5273}, year = {2014}, date = {2014-02-01}, urldate = {2014-02-08}, journal = {International Journal of Production Economics}, volume = {148}, pages = {62--70}, abstract = {This paper deals with the coordination of manufacturing, remanufacturing and returns acceptance control in a hybrid production-inventory system. We use a queuing control framework, where manufacturing and remanufacturing are modelled by single servers with exponentially distributed processing times. Customer demand and returned products arrive in the system according to independent Poisson processes. A returned product can be either accepted or rejected. When accepted, a return is placed in a remanufacturable product inventory. Customer demand can be satisfied as well by new and remanufactured products. The following costs are included: stock keeping, backorder, manufacturing, remanufacturing, acceptance and rejection costs. We show that the optimal policy is characterized by two state-dependent base-stock thresholds for manufacturing and remanufacturing and one state-dependent return acceptance threshold. We also derive monotonicity results for these thresholds. Based on these theoretical results, we introduce several relevant heuristic control rules for manufacturing, remanufacturing and returns acceptance. In an extensive numerical study we compare these policies with the optimal policy and provide several insights.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper deals with the coordination of manufacturing, remanufacturing and returns acceptance control in a hybrid production-inventory system. We use a queuing control framework, where manufacturing and remanufacturing are modelled by single servers with exponentially distributed processing times. Customer demand and returned products arrive in the system according to independent Poisson processes. A returned product can be either accepted or rejected. When accepted, a return is placed in a remanufacturable product inventory. Customer demand can be satisfied as well by new and remanufactured products. The following costs are included: stock keeping, backorder, manufacturing, remanufacturing, acceptance and rejection costs. We show that the optimal policy is characterized by two state-dependent base-stock thresholds for manufacturing and remanufacturing and one state-dependent return acceptance threshold. We also derive monotonicity results for these thresholds. Based on these theoretical results, we introduce several relevant heuristic control rules for manufacturing, remanufacturing and returns acceptance. In an extensive numerical study we compare these policies with the optimal policy and provide several insights. |
2013 |
Vercraene, Samuel; Gayon, Jean-Philippe Optimal control of a production-inventory system with product returns Journal Article International Journal of Production Economics, 142 (2), pp. 302–310, 2013, ISSN: 0925-5273. @article{vercraene_optimal_2013, title = {Optimal control of a production-inventory system with product returns}, author = {Samuel Vercraene and Jean-Philippe Gayon}, url = {https://samuel.vercraene.fr/work/wp-content/uploads/2018/03/MakeToStockQueueWithProductReturns-1.pdf}, doi = {10.1016/j.ijpe.2012.11.012}, issn = {0925-5273}, year = {2013}, date = {2013-04-01}, urldate = {2013-02-19}, journal = {International Journal of Production Economics}, volume = {142}, number = {2}, pages = {302--310}, abstract = {We consider a production-inventory system that consists of n stages. Each stage has a finite production capacity modelled by an exponential server. The downstream stage faces a Poisson demand. Each stage receives returns of products according to independent Poisson processes that can be used to serve demand. The problem is to control production to minimize discounted (or average) holding and backordering costs. For the single-stage problem (n=1), we fully characterize the optimal policy. We show that the optimal policy is base-stock and we derive an explicit formula for the optimal base-stock level. For the general n-stage problem, we show that the optimal policy is characterized by state-dependent base-stock levels. In a numerical study, we investigate three heuristic policies: the base-stock policy, the Kanban policy and the fixed buffer policy. The fixed-buffer policy obtains poor results while the relative performances of base-stock and Kanban policies depend on bottlenecks. We also show that returns have a non-monotonic effect on average costs and strongly affect the performances of heuristics. Finally, we observe that having returns at the upstream stage is preferable in some situations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We consider a production-inventory system that consists of n stages. Each stage has a finite production capacity modelled by an exponential server. The downstream stage faces a Poisson demand. Each stage receives returns of products according to independent Poisson processes that can be used to serve demand. The problem is to control production to minimize discounted (or average) holding and backordering costs. For the single-stage problem (n=1), we fully characterize the optimal policy. We show that the optimal policy is base-stock and we derive an explicit formula for the optimal base-stock level. For the general n-stage problem, we show that the optimal policy is characterized by state-dependent base-stock levels. In a numerical study, we investigate three heuristic policies: the base-stock policy, the Kanban policy and the fixed buffer policy. The fixed-buffer policy obtains poor results while the relative performances of base-stock and Kanban policies depend on bottlenecks. We also show that returns have a non-monotonic effect on average costs and strongly affect the performances of heuristics. Finally, we observe that having returns at the upstream stage is preferable in some situations. |
2012 |
Flapper, Simme Douwe P; Gayon, Jean-Philippe; Vercraene, Samuel Control of a production–inventory system with returns under imperfect advance return information Journal Article European Journal of Operational Research, 218 (2), pp. 392–400, 2012, ISSN: 0377-2217. @article{flapper_control_2012, title = {Control of a production\textendashinventory system with returns under imperfect advance return information}, author = {Simme Douwe P Flapper and Jean-Philippe Gayon and Samuel Vercraene}, url = {http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.459.6766&rep=rep1&type=pdf}, doi = {10.1016/j.ejor.2011.10.051}, issn = {0377-2217}, year = {2012}, date = {2012-04-16}, urldate = {2018-03-18}, journal = {European Journal of Operational Research}, volume = {218}, number = {2}, pages = {392--400}, abstract = {We consider a production\textendashinventory system with product returns that are announced in advance by the customers. Demands and announcements of returns occur according to independent Poisson processes. An announced return is either actually returned or cancelled after a random return lead time. We consider both lost sale and backorder situations. Using a Markov decision formulation, the optimal production policy, with respect to the discounted cost over an infinite horizon, is characterized for situations with and without advance return information. We give insights in the potential value of this information. Also some attention is paid to combining advance return and advance demand information. Further applications of the model as well as topics for further research are indicated.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We consider a production–inventory system with product returns that are announced in advance by the customers. Demands and announcements of returns occur according to independent Poisson processes. An announced return is either actually returned or cancelled after a random return lead time. We consider both lost sale and backorder situations. Using a Markov decision formulation, the optimal production policy, with respect to the discounted cost over an infinite horizon, is characterized for situations with and without advance return information. We give insights in the potential value of this information. Also some attention is paid to combining advance return and advance demand information. Further applications of the model as well as topics for further research are indicated. |
Conferences
2016 |
Ladier, Anne-Laure; Vercraene, Samuel; Cheutet, Vincent; Dachicourt, Rémi Planification et gestion des flux de déchets issus du démantèlement dínstallations nucléaires Conference ROADEF 2016, Compiègne, France, 2016. @conference{anne-laure_ladier_planification_2016, title = {Planification et gestion des flux de d\'{e}chets issus du d\'{e}mant\`{e}lement d\'{i}nstallations nucl\'{e}aires}, author = {Anne-Laure Ladier and Samuel Vercraene and Vincent Cheutet and R\'{e}mi Dachicourt}, year = {2016}, date = {2016-02-01}, booktitle = {ROADEF 2016}, address = {Compi\`{e}gne, France}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
Tellez, Oscar; Vercraene, Samuel; Lehuédé, Fabien; Péton, Olivier; Monteiro, Thibaud ROADEF 2016, Compiègne, France, 2016. @conference{tellez:hal-01314741, title = {Optimisation du transport mutualis\'{e} d'enfants en situation de handicap avec v\'{e}hicules reconfigurables}, author = {Oscar Tellez and Samuel Vercraene and Fabien Lehu\'{e}d\'{e} and Olivier P\'{e}ton and Thibaud Monteiro}, url = {https://hal.archives-ouvertes.fr/hal-01314741}, year = {2016}, date = {2016-02-01}, booktitle = {ROADEF 2016}, address = {Compi\`{e}gne, France}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
2013 |
Vercraene, Samuel; Gayon, Jean-Philippe; Karaesmen, Fikri Analyse de sensibilité dans une classe de processus de décision markoviens Conference ROADEF 2013, Troyes, France, 2013. @conference{vercraene:hal-00789175, title = {Analyse de sensibilit\'{e} dans une classe de processus de d\'{e}cision markoviens}, author = {Samuel Vercraene and Jean-Philippe Gayon and Fikri Karaesmen}, url = {https://hal.archives-ouvertes.fr/hal-00789175}, year = {2013}, date = {2013-01-01}, booktitle = {ROADEF 2013}, address = {Troyes, France}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
2011 |
Vercraene, Samuel; Gayon, Jean-Philippe A two-stage production/inventory system with admission control of product returns Conference IESM 2011, Metz, France, 2011, (ISBN 978-2-9600532-3-4). @conference{vercraene:hal-00789176, title = {A two-stage production/inventory system with admission control of product returns}, author = {Samuel Vercraene and Jean-Philippe Gayon}, url = {https://hal.archives-ouvertes.fr/hal-00789176}, year = {2011}, date = {2011-05-25}, booktitle = {IESM 2011}, pages = {537}, address = {Metz, France}, note = {ISBN 978-2-9600532-3-4}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
Vercraene, Samuel; Karaesmen, Fikri; Gayon, Jean-Philippe Analyse de sensibilité d'un système de contrôle d'admission Conference ROADEF 2011, Saint-Étienne, France, 2011. @conference{vercraene_analyse_2011, title = {Analyse de sensibilit\'{e} d'un syst\`{e}me de contr\^{o}le d'admission}, author = {Samuel Vercraene and Fikri Karaesmen and Jean-Philippe Gayon}, url = {http://hal.archives-ouvertes.fr/index.php?action_todo=search&view_this_doc=hal-00579911&version=1&halsid=rr32bfob5jd31hm7jnqqi8aoh1}, year = {2011}, date = {2011-03-02}, urldate = {2011-03-25}, booktitle = {ROADEF 2011}, address = {Saint-\'{E}tienne, France}, abstract = {Ce papier se focalise sur la classe des probl\`{e}mes de contr\^{o}le de files d\'{a}ttente. En g\'{e}n\'{e}ral l\'{o}bjectif est de minimiser l\'{e}sp\'{e}rance d'un co\^{u}t ou maximiser l\'{e}sp\'{e}rance d'un gain en contr\^{o}lant le nombre d'\'{e}l\'{e}ments (produits, clients...) dans la file d\'{a}ttente. Il existe des r\'{e}sultats analytiques sur la structure (forme globale) de la politique optimale. Nous nous int\'{e}ressons ici \`{a} l\'{a}nalyse de sensibilit\'{e} de ces syst\`{e}mes.}, keywords = {}, pubstate = {published}, tppubtype = {conference} } Ce papier se focalise sur la classe des problèmes de contrôle de files dáttente. En général lóbjectif est de minimiser léspérance d'un coût ou maximiser léspérance d'un gain en contrôlant le nombre d'éléments (produits, clients...) dans la file dáttente. Il existe des résultats analytiques sur la structure (forme globale) de la politique optimale. Nous nous intéressons ici à lánalyse de sensibilité de ces systèmes. |
2010 |
Vercraene, Samuel; Gayon, Jean-Philippe; Jemai, Zied Control of a two-stage production/inventory system with products returns Conference IFAC LSS 12, 9 (1), Villeneuve d'Ascq, France, 2010. @conference{vercraene:hal-00579897, title = {Control of a two-stage production/inventory system with products returns}, author = {Samuel Vercraene and Jean-Philippe Gayon and Zied Jemai}, url = {https://hal.archives-ouvertes.fr/hal-00579897}, doi = {10.3182/20100712-3-FR-2020.00039}, year = {2010}, date = {2010-07-12}, booktitle = {IFAC LSS 12}, volume = {9}, number = {1}, pages = {232-237}, address = {Villeneuve d'Ascq, France}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
PhD Thesis
2012 |
Vercraene, Samuel Control of production/inventory systems in reverse logistic context PhD Thesis Grenoble University, 2012. @phdthesis{vercraene:tel-00789181, title = {Control of production/inventory systems in reverse logistic context}, author = {Samuel Vercraene}, url = {https://tel.archives-ouvertes.fr/tel-00789181}, year = {2012}, date = {2012-10-01}, number = {2012GRENI046}, school = {Grenoble University}, abstract = {Flows of returns due to recycling and reusing waste are developing in order to preserve the limited natural resources of our planet. These new flows interact with the traditional production flows. Therefore, in order to provide customers with the best service level and minimize the stock in the supply chain, the control of the return flows appears to be of highest importance. We address this problem by modeling a situation with a limited production capacity and we consider an operational production/inventory problem that incorporates flows of returns. We model three continuous-time production/inventory problems with limited production capacities, random lead times, and linear costs. In the first problem we take into account the probability that a product can be reused as a finished product or only as semi-finished product (by parts), in the second problem we include a step of remanufacturing before reusing the returned product, and in the third problem we consider a system with product returns that are announced in advance by the customers. Apart from the characterization of the optimal policies for these cases, the performance assessments of some heuristic policies and the study of the poduction capacity effect on these heuristic policies stand as main contributions. Throughout this work we have used existing tools to characterize optimal policies for different Markov decision processes. The last chapter aims to improve these tools and enable us to study the influence of several system parameters on it s optimal policy.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } Flows of returns due to recycling and reusing waste are developing in order to preserve the limited natural resources of our planet. These new flows interact with the traditional production flows. Therefore, in order to provide customers with the best service level and minimize the stock in the supply chain, the control of the return flows appears to be of highest importance. We address this problem by modeling a situation with a limited production capacity and we consider an operational production/inventory problem that incorporates flows of returns. We model three continuous-time production/inventory problems with limited production capacities, random lead times, and linear costs. In the first problem we take into account the probability that a product can be reused as a finished product or only as semi-finished product (by parts), in the second problem we include a step of remanufacturing before reusing the returned product, and in the third problem we consider a system with product returns that are announced in advance by the customers. Apart from the characterization of the optimal policies for these cases, the performance assessments of some heuristic policies and the study of the poduction capacity effect on these heuristic policies stand as main contributions. Throughout this work we have used existing tools to characterize optimal policies for different Markov decision processes. The last chapter aims to improve these tools and enable us to study the influence of several system parameters on it s optimal policy. |