The A Priori Dynamic Traveling Salesman Problem with Time Windows

The remarkable advances in telecommunications and information technology have enabled companies to focus on velocity and timeliness throughout the supply chain. To achieve these competitive advantages, they must be able to make effective use of the vast amount of real-time information now available to them. The Dynamic Vehicle Routing Problem (DVRP) is a prime example of a distribution context where intelligent use of real-time information can differentiate one company from another by means of superior on-time service. The DVRP is the dynamic counterpart of the traditional vehicle routing problem where several vehicles must visit and service a number of customers. Constraints such as capacity restrictions, time windows within which to start service at customers and additional requirements on the drivers and vehicles must be accounted for when seeking to minimize the travel cost. In contrast to the generic, or static, vehicle routing problem where the dispatcher can plan ahead, in the dynamic version, part or all of the necessary information becomes available only during the day of operation. The practical significance of the DVRP is highlighted by the variety of environments it can model. An important application is the pick-up and delivery of overnight mail. Other scenarios include the distribution of heating oil or liquid gas to private households, residential utility repair