A Variable Neighborhood Search for the Vehicle Routing Problem with Time Windows and Preventive Maintenance Activities

In this paper we address a vehicle routing problem with time windows (VRPTW) with preventive maintenance (VRPTW-PM) and we propose a mathematical formulation for this problematic situation as well as a variable neighborhood search (VNS) metaheuristic to be solved. First, we solve the standard VRPTW with 100 customer solomon benchmark to produce the original plan, then we introduce maintenance activity to the vehicle that made the longest distance based on the original plan. A scheduling model is presented based on the VNS metaheuristic for the vehicle routing problem with time windows when one or more vehicles require preventive maintenance activities after the supply of a set of customers. Computational results show the efficiency of the proposed approach.