An Exact Algorithm for the Period Routing Problem

This paper presents an exact algorithm for solving strategic and tactical multiperiod vehicle routing problems that can be modeled as period vehicle routing problems (PVRPs). The PVRP is defined on a time horizon of several days and consists of assigning appropriate combinations of delivery to customers and designing a set of delivery routes for every day of the planning period. The objective is to service all customers assigned to each day minimizing the overall routing cost. This paper describes an integer programming formulation of the PVRP that is used to derive different lower bounds and an exact solution method. Computational results on test instances from the literature and on new sets of test instances show the effectiveness of the proposed method.