In the logistics network design problem (LNDP), decisions must be made regarding the selection of suppliers, the location of plants and warehouses, the assignment of activities to these facilities, and the flows of raw materials and finished products in the network. This article introduces an iterated local search (ILS) heuristic for the LNDP variant arising when each raw material should be supplied by a unique supplier, and each finished product should be produced and distributed by a unique plant and a unique warehouse, respectively. The ILS heuristic exploits the combinatorial nature of the problem and relies on simple moves combined within a descent algorithm. Several perturbation operators are used to allow a broad exploration of the solution space. The performance of the algorithm is evaluated on randomly generated instances, and the solutions are compared with lower bounds computed by solving the LP relaxation of the problem.

The Uncapacitated Facility Location Problem (UFLP) is one of the most widely studied discrete location problems, whose applications arise in a variety of settings. We tackle the UFLP using probabilistic inference in a graphical model- an approach that has received little attention in the past. We show that the fixed points of max-product linear programming (MPLP), a convexified version of the max-product algorithm, can be used to construct a solution with a 3-approximation guarantee for metric UFLP instances. In addition, we characterize some scenarios under which the MPLP solution is guaranteed to be globally optimal. We evaluate the performance of both max-sum and MPLP empirically on metric and non-metric problems, demonstrating the advantages of the 3-approximation construction and algorithm applicability to non-metric instances.

In agricultural industry, a collector has to collect more raw material quantity in order to get higher income since the price of raw material is quantity dependent. In this paper, we consider multi–location allocation problem for inbound collection system in which agricultural product is collected from suppliers and transported to a factory through collector system. The mathematical model which maximizes profit is formulated. The basis trade–off of the model is between revenue from collected raw material and total system costs which include both set up cost and variable cost. Some numerical examples are applied to test the proposed model.

Abstract — Logistics networks configuration is such kind of problems concerning facility location, production and distribution planning along the whole process of material flow. Abundant research has been done in this field from modeling by considering different scenarios to methods such as different heuristic methods. However, the models do not consider the influence of the important postponement strategy on logistics networks in the era of mass customization. Furthermore, the multi-commodity models till now do not consider the influence of commonality among products. In this paper, a logistics network model considering product commonality and postponement is formulated. This model is expected to be used to analyze the impacts of commonality and postponement strategies on location-allocation decisions in logistics network planning. Index Terms—logistics network planning, location allocation, commonality, postponement. I.

Can modeling of HIV treatment processes improve outcomes? Capitalizing on an operations research approach to the global pandemic

Abstract — Logistics networks configuration is such kind of problems concerning facility location, production and distribution planning along the whole process of material flow. Abundant research has been done in this field from modeling by considering different scenarios to methods such as different heuristic methods. However, the models do not consider the influence of the important postponement strategy on logistics networks in the era of mass customization. Furthermore, the multi-commodity models till now do not consider the influence of commonality among products. In this paper, a logistics network model considering product commonality and postponement is formulated. This model is expected to be used to analyze the impacts of commonality and postponement strategies on location-allocation decisions in logistics network planning. Index Terms—logistics network design, location allocation, supply chain, commonality, postponement. I.

RESUME: La conception de chaînes logistiques vertes consiste en la considération de critères environnementaux lors de la prise de décisions stratégiques sur la localisation d’usines ou d’entrepôts logistiques. Dans ce travail, une approche multi-objective est développée pour l’optimisation simultanée des coûts économiques globaux ainsi que de l’impact environnemental des configurations des réseaux. L’idée est innovante à deux titres. Tout d’abord elle s’applique aux modèles de chaînes logistiques générales, qu’elles soient traditionnellement directes ou en boucle fermée, intégrant ainsi les opérations logistiques inverses. Par ailleurs, l’approche gère l’impact environnemental du transport dans le modèle global d’optimisation de la chaîne logistique verte. Plus particulièrement, en supplément de la fonction objective qui calcule les coûts économiques de la chaîne logistique, nous considérons une seconde fonction objective qui prend en compte les coûts externes du transport. Ces coûts représentent les dommages causés à l’environnement tels que la pollution atmosphérique qui n’étaient jusqu’alors pas payés et ont donc été négligés dans le processus de décision. Cependant, avec les nouvelles régulations concernant l’environnement, les entreprises ont à présent le devoir et l’obligation de tenir compte des changements climatiques dans leurs décisions commerciales de tous les jours. MOTS-CLES: Chaînes logistiques vertes, conception de réseaux, formulation multi-objective, coûts environnementaux du transport.