An Improved PSO for the Multi-Depot Vehicle Routing Problem with Time Windows

The distribution of finished products from depots to customers is a practical and challenging problem in logistics management. Better routing and scheduling decisions can result in higher level of customer satisfaction. The distribution problem is generally formulated as the vehicle routing problem (VRP). Nevertheless, there is a rigid assumption that there is only one depot. In cases, for instance, where a logistics company has more than one depot, the VRP is not suitable. To resolve this limitation, this paper focuses on the VRP with multiple depots with time windows, (MDVRPTW). The MDVRP is NP-hard, which means that an efficient algorithm for solving the problem to optimality is unavailable. To deal with the problem efficiently, improved PSO is developed in this paper. A computational study is carried out to verify the algorithms. It is proved that the performance of improved PSO can solve this problem efficiently.