Mathematical Modelling Approaches for Integrated Single Machine Scheduling and Electric Vehicle Routing Problem
İclal Bağcı, Hande Öztop, Zeynel Abidin ÇilIn recent years, increasingCO2 emissions and resource utilization has adversely affected the environment. Sustainability efforts have been initiated to decrease these effects, including environmentally friendly electric vehicles in vehicle fleets used for transportation. The electric vehicle routing problem (EVRP) has emerged in the literature, and numerous studies have been conducted, considering specific constraints related to electric vehicles. Due to various charging feature constraints, EVRP diverges from the classical vehicle routing problem (VRP) and becomes more complex. In addition to the load capacity constraints of classical VRP, electric vehicles must deliver products to customers via an optimal vehicle route while considering battery capacity limitations. This study addresses the integrated single-machine scheduling and electric vehicle routing problem. After scheduling and processing customer product requests on a single machine, electric vehicle routes must be created to deliver these products to customers. To meet customer expectations, the objective function of the problem aims to minimize the costs associated with customer product delivery delays. Two mathematical models, i.e., mixed-integer linear programming (MILP) and constraint programming (CP) models, are presented to solve this problem. The results and performances of these models are compared on a set of instances. Numerical results indicate that the CP model has superior performance than the MILP model for the problem.