With the development of the global business in the 21st century, the areas ofsupply chain management have extended to the usage and the end-of-life stage ofproduct ,which yields the development of the so called closed-loop supply chain .As a result, how to improve the efficiency of the whole closed-loop supply chain hasattracted great attention of enterprises as well as scholars.Based on the analysis of existing study ,this thesis focuses on the networkdesign of closed-loop supply chain .We pay particular attention to the networkdesign of product recovery and the third-party logistics providers.We first study the network design of product returns in a closed-loop supplychain.We establish a mixed integer programming model involving customers, col-lection points ,collection center and service time .We propose a genetic algorithmto solve the problem that minimize the return cost and rationalize the networkstructure of product recovery.We then study the network design of third-party logistics providers.Becausethird-party logistics providers in the management of closed-loop supply chain playa very important role a nonlinear mixed integer programming model involving cus-tomers, mixed distribution centers and plants is introduced and a genetic algorithmis presented to solve it.thus we dynamically integrate the supply chain and enhancethe efficiency of whole closed-loop supply chain.We also do numerical simulations to test the proposed models.The results thatour study is in an accordance with the real situation. |