Research on the Multi-Depot Vehicle Routing Problem

The distribution of finished products from depots to customers is a practical and challenging problem in logistics management. Better routing and scheduling decision can result in higher level of customer satisfaction because more customers can be served in a shorter time. The distribution problem is generally formulated as the vehicle routing problem (VRP). The multi-depot vehicle routing problem (MDVRP) is a generalization of the single-depot vehicle routing problem (SDVRP) in which vehicles start from multiple depots and return to their depots of origin at the end of their assigned tours with the minimum cost. This paper focuses on the VRP with multiple depots, we present region partition heuristic method to divide the region composed by depots and nodes ( customers). Then, we propose the general model of time-limited TSP problem to find an optimal time-limited TSP tour. for each vehicle and the nodes in the same subregion. Finally, the method is clearly illustrated by practical cases.