Research On Network Equilibrium Of Repairable Products Reverse Logistics Based On Robust Optimization

During the operation of reverse logistics network for repairable products, recycling time, recovery rate and the quality of waste are often with uncertainty. These uncertainties have important influence on the overall effectiveness of reverse logistics for repairable products. Therefore, in this thesis, we analyze a variety of uncertain factors during the operation of reverse logistics network for repairable products, constraint conditions, cost elements of maintaining the operation of the network and the produced revenue. Under the environment of uncertainty, in order to realize cost minimization and profit maximization during the operation of network, robust optimization theory are employed to develop reverse logistics network for repairable products and reverse logistics network for re-manufacturing. The content includes:1. We generalize the relevant studies of reverse logistics network under the environment of uncertainty and some applications of robust optimization in network optimization decision. We also introduce the relevant basic theory: robust optimization method.2. Under the environment of uncertain product recovery, this thesis studies reverse logistics network for repairable products. We design the network structure diagram of reverse logistics network for repairable products with a variety of products, recycling center, re-processing center, processing center and waste disposal center. Under the environment of certainty, optimization model of reverse logistics network for repairable products is proposed. In the case of product recovery with the uncertainty, this thesis constructs a robust optimization model. The existence of solutions of the robust optimization model is analyzed.3. Under the environment of uncertain unit transportation cost and the quantity of used products, this thesis studies reverse logistics network for re-manufacturing. Firstly, we design the network structure diagram of reverse logistics network for re-manufacturing. Secondly, optimization model of reverse logistics network for re-manufacturing under the environment of certainty is proposed. Thirdly, considering the uncertainty of unit transportation cost and the quantity of used products, robust optimization model is constructed. Finally, the robust optimization problem is translated into linear programming problem, the existence of solutions of the robust optimization model is proved.4. We propose the algorithm to solve the robust optimization model of reverse logistics network for re-manufacturing which has been established before. We provide an instance, apply LINDO6.1 to solve the model, and analyze the results to illustrate the effectiveness of robust optimization method.