Publications

@article{ribault_economic_2020,

title = {Economic optimisation of cold production: a matheuristic with artificial neural network approach},

author = {Alnour Ribault and Samuel Vercraene and S\'{e}bastien Henry and Yacine Ouzrout},

url = {https://doi.org/10.1080/00207543.2020.1831705},

doi = {10.1080/00207543.2020.1831705},

issn = {0020-7543},

year  = {2020},

date = {2020-10-23},

urldate = {2020-11-13},

volume = {0},

number = {0},

pages = {1--22},

abstract = {In this paper, the economic optimisation of cold storage is studied. A modern cold room is mainly composed of compressors, a tank to store heat-transfer fluid and cold rooms. The main cost is incurred by energy consumption and maintenance. The price of electricity, which is known in advance, varies during the day. Production schedules that entail higher risks of compressor wear, and thus high maintenance costs, have to be avoided. The temperature inside the cold rooms must be maintained within the allowed range, and complex thermodynamic processes make it difficult to predict temperature. The tank has a limited capacity. This paper presents the first model optimising the management cost of a cold store with a tank. Maintenance costs are considered for compressors, and Artificial Neural Networks are used to forecast the temperatures in the cold rooms. An optimal Dynamic Programme is designed for the case with one cold room and a matheuristic algorithm is presented for the general case with several cold rooms. A comparison with a classical hysteresis controller shows significant savings. The impact of storage capacity on operating costs is evaluated, after which the influence of the maintenance cost value is discussed.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{tellez_stakeholder_2020,

title = {A stakeholder oriented approach to the optimization of transports of people with disabilities},

author = {Oscar Tellez and Laurent Daguet and Fabien Lehu\'{e}d\'{e} and Thibaud Monteiro and Geovanny Osorio Montoya and Olivier P\'{e}ton and Samuel Vercraene},

url = {https://hal.archives-ouvertes.fr/hal-02546111},

doi = {10.1080/16258312.2020.1768435},

year  = {2020},

date = {2020-06-12},

urldate = {2020-11-13},

volume = {21},

number = {2},

pages = {93--102},

abstract = {From 2010, the health transportation in France has become one of the top ten priorities of the risk management plan due to the increasing cost of these transports. For social and Medico-Social Institutions (MSI), this cost represents the second-biggest expense after that of the wages. In this context, the NOMAd project aims to improve the daily transportation service for people with disabilities between their home to MSI. To this end, we performed a field survey to identify the needs of the different stakeholders. This survey allows us to propose the transportation pooling among several MSIs on one side, and a global transport management process on the other side. This process makes possible to group and optimize routes on a given geographical area. The challenge is then to improve economic performance while maintaining social and environmental goals. A decision aiding tool for the transport optimization is proposed to tackle this problem.},

note = {Publisher: Kedge Business School},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}