Vehicle routing problems with inter-tour resource constraints

Abstract

Inter-tour constraints are constraints in a vehicle-routing problem (VRP) on globally limited resources that different vehicles compete for. Real-world examples are a limited number of "long" tours, where long is defined with respect to the traveled distance, the number of stops, the arrival time at the depot etc. Moreover, a restricted number of docking stations or limited processing capacities for incoming goods at the destination depot can be modeled by means of intertour resource constraints. In this chapter, we introduce a generic model for VRPs with inter-tour constraints based on the giant-tour representation and resourceconstrained paths. Furthermore, solving the model by efficient local search techniques is addressed: Tailored preprocessing procedures and feasibility tests are combined into local-search algorithms, that are attractive from a worst-case point of view and are superior to traditional search techniques in the average case. In the end, the chapter provides results for some new types of studies where VRPs with time-varying processing capacities are analyzed. © Springer Science+Business Media, LLC 2008.