LOCATING REMANUFACTURING AND WAREHOUSE CENTERS IN THE INTEGRATED FORWARD AND REVERSE LOGISTIC CONSIDERING STOCHASTIC DEMANDS AND LIMITED CAPACITIES

One of the most important issues of location is locating the facilities in two types of problem: facility location problems with limited capacity and non-limited capacity.The objective of these problems is to nd the best and most suitable location for facilities. In this paper, with studying various models for locating with in forward and reverse logistics systems and also reviewing recent papers in this area, we proposed an integrated model in facility location in which \forward" and \reverse" networks are considered simultaneously. In this model, we consider producers, intermediate centers, and remanufacturing centers, and warehouse centers simultaneously which are to be located in an integrated logistics system with limited capacities. To model this problem in this study, we propose a 0-1 mixed integer programming model in which forward and reverse ows and their mutual interactions are considered simultaneously. In this problem, customer demands are considered as stochastic, and demands for this model contain new products and returned products. To examine the eciency, the mixed 0-1 and integer programming models, various test problems, and numerical calculations are solved by GAMS 24.1.2 optimization software. To show the eectiveness of this model, we have considered the test problem extended to Bostel and Lu study in 2007 in which forward and reverse networks are consideredsimultaneouslywithrespecttotheremanufacturing centers. By comparing the numerical results obtained from the model, it was shown that the proposed model provides a more optimal solution. To satisfy customer demandsregardingreturnedproducts,wefocusedonthe remanufacturing centers. In the study, we also showed that considering the facilities simultaneously would directly aect reverse logistics network structure. Also, the cost of production and remanufacturing centers affect the total cost of logistic network, such that by increasing the percentage of remanufacturing due to lower production costs, the total cost of network is reduced. So, with appropriate decision making and correct information about choosing the recovery facility (remanufacturing centers), returned products can be as many as possible to remanufacture and repair the damage, and thus avoid extra production costs.