Multi-period Vehicle Routing Problems with Consistent Service Constraints
The design and implementation of periodic customer service systems has become a crucial concern for modern companies seeking to provide high quality - yet low cost - services to their customers. Optimizing repetitive customer service operations over multiple days, such as parcel deliveries and courier services, home care and nursing services, vending machine replenishment, cleaning services and building maintenance, can add up to significant cost savings through the maximum utilization of equipment and personnel. This talk will focus on a challenging multi-period vehicle routing problem with consistent service constraints that has recently attracted a lot of attention from the academic and industrial community. A novel mathematical programming formulation will be presented that facilitates a heuristic hierarchical decomposition of the problem into smaller manageable sub-problems, as well as advances on the algorithmic front that include a collaborative scheme between Tabu Search metaheuristic algorithms and an exact Branch-and-Cut framework. The proposed methods exhibit strong computational performance as evidenced by their ability to obtain new best solutions for a number of benchmark problems that have previously appeared in literature.