A Hybrid Solution Method for Hub-and-Spoke Network Design under Uncertainty

Supply chain is an integrated system of facilities and activities. Gaining the optimum design of demand satisfaction network is one of the most important live issues in the decision making problems category. Most of previous studies considered unreal assumptions such as the lack of capacity constraints to satisfy demand in the network and in hubs. By considering the nature of the case that have been studied in this research, the assumption of unlimited capacity to satisfy the demand is justified. Another common assumption in hub location problems is the lack of direct connection between the nodes. In this research and in real world problems would be seen that the direct link between the nodes can be effective in reducing system costs and increase the efficiency of the network. The other innovations of current research is considering uncertain nature of the demand data, oscillation and changes in costs anticipation and actual hub establishing costs, fuzzy numbers are used to represent these values. Problem modeling is held in a fuzzy state and a hybrid method is represented to solve the problem. At first, defuzzification of the model is taken place. Afterwards, all possible answers are considered with the help of the Genetic Algorithm. At last, the optimum case were chosen by using VIKOR ranking method. Calculation results for the designing of optical fiber network between cities are showing good and acceptable performance of the proposed method in an acceptable solving time.