A dynamic multi-period general routing problem arising in postal service and parcel delivery systems

Postal and courier companies are under the pressure of minimizing operational costs while meeting requests for increasingly high service levels. We model their delivery problem as a dynamic multi-period general routing problem (DMPGRP) with the aim of minimizing the total cost over a given planning horizon. In most modern delivery systems, fluctuating demand volumes dynamically reveal themselves over time; in addition, service differentiation is highly important. Both these characteristics are considered in our DMPGRP. An effective solution strategy for this problem selects demands that must be fulfilled day by day, after distinguishing them according to priority classes. It then constructs the vehicle routes by using a heuristic algorithm based on the adaptive large neighbourhood search. The results of an extensive computational study are reported.