Research On Reverse Logistics Facility Location Of Concering Closed-loop Supply Chain Based On Lagrangian Relaxation Algorithm

With continuous improvement of laws and regulations on recycling economic system, more and more enterprises will take the responsibility for recycling products. So based on the above background and the research results obtained, considering the affection between reverse and forward logistcs, closed-loop supply chains have been analyzed and the location problem of reverse logistics network within closed-loop supply chains has been studied.The first part is the introduction of the context. The background and meaning of the thesis are pointed out. Then the research status of closed-loop supply chain, facility location problem and location models in domestic and aborad is introduced. Finally, we proposed the ideas and content of research.The second part introductions the basic knowledge for the research on the reverse logistics facility location of concering closed-loop supply chain. Reverse logistics, closed-loop supply chain and facility locaton aspects are outlined.The third part is the building of a logistics facility location model for the two level closed-loop chain,in which the forward logistics and reverse logistics simultaneously affect each other. Before the establishment of model, first proposed facility location models are analyzed and compared; Then according to the remanufacturing logistics facility location of concering closed-loop supply chain we build a facility location model to determine the address of production factory, manufacturing center and transit center. The objective function is to make the total cost of logistics activities is the lowest.The forth part is the algorithm design. The paper describes the model used to solve facility location problems and the basic priciples of Lagrangian heuristics; Because the basic Lagrangian relaxation algorithm for solving the model established by this paper is not ideal, so on the basis of this algorithm, we make some improvements when solving the lower bound of the objective function to get a new algorithm, and the new algorithm is applied to the sovling of the model proposed in this paper, we also propose the steps to solve the problem.The fifth part is the example shows. We quote a typical example for the study. According to the algorithm we desigen a comprter program to solve this example and obtain the best location of the facilities, at the same time the effectity of the algorithm is proved. The algorithm for solving the model performs more excellent in speed.