A study of the Multi-Trip vehicle routing problem with time windows and heterogeneous fleet

This article introduces a metaheuristic approach to solve a variation of the well-known Vehicle Routing Problem (VRP). We present a solution for the Multi-Trip VRP with Time Windows and Heterogeneous Fleet. We add constraints to the original VRP concerning the time and the customer supply. Time constraints concerns the time windows on each customer and time horizon within which customers must be satisfied. In respect of the customer supply, we consider a heterogeneous fleet where vehicles are allowed to do multiple trips. We propose a solution for the problem using a Local Search and the Simulated Annealing technique. In order to evaluate the performance of our approach, we tested the procedure on a set of benchmark scenarios widely used for the VRP.