On service consistency in multi-period vehicle routing

In this paper, we investigate a new variant of the vehicle routing problem (VRP), termed the multi-period vehicle routing problem with time windows and limited visiting quota (MVRPTW-LVQ), which requires that any customer can be served by at most a certain number of different vehicles over the planning horizon. We first formulate this problem as a mixed integer programming model and then devise a three-stage heuristic approach to solve the...