Crossdock truck scheduling with time windows: earliness, tardiness and storage policies

This article proposes to simultaneously plan inbound and outbound truck arrivals and departures in a cross-docking platform, as well as the internal pallet handling. The objective is to minimize both the total number of pallets put in storage and the dissatisfaction of the transportation providers, by creating a truck schedule as close as possible to the wished schedule they communicate in advance. The problem is modeled with an integer program tested on generated instances to assess its performance, especially regarding the computation time. The problem is proven to be np -hard in the strong sense. Since the execution takes too long to be used on a daily basis by platform managers, three heuristics are also proposed and tested. Two are based on integer programs solved sequentially, the third one is a tabu search in which the storage part of the objective function is evaluated by a maximum flow model in a graph. Numerical experiments show in which conditions each heuristic performs best, which can help choosing a solution method when confronted to a real-life problem.