Advances in the Electric Vehicle Routing Problem: A New Exact Formulation and GRASP for Heterogeneous Fleet with Fractional Deliveries

Studies in Smart and Sustainable Cities and Regions have become fundamental to addressing challenges related to mobility, sustainability, and service efficiency. In this context, the Vehicle Routing Problem (VRP) emerges as a challenge for optimizing logistics systems, contributing to the reduction of operational costs and pollutant emissions. This work presents efficient algorithms for the Electric Vehicle Routing Problem with a Heterogeneous Fleet and Split Deliveries, a little-explored variant of the classic VRP. Unlike the traditional approach, the fleet is composed of electric vehicles with different capacities and costs, in addition to the possibility of demand fractionation. Initially, a new exact mathematical model that formalizes the problem is proposed, followed by a GRASP heuristic with Randomized Variable Neighborhood Descent (RVND). The performance of the proposed approach is evaluated through computational experiments on benchmark instances from the literature, which prove the efficiency of the methods.