A Model and Metaheuristic for Truck Scheduling in Multi-door Cross-dock Problems

The cross-docking is a warehousing strategy where trucks arrive from suppliers to unload, regroup, and reload their items onto trucks going to the customers. There is a common assumption that the receiving (shipping) dock has only one single door, but companies usually duplicate doors in parallel to expedite operations. This paper studies the problem of scheduling trucks in the cross-dock with multiple inbound and outbound doors with makespan minimization. The problem is first formulated by a new mixed integer programming model. Using the model, small instances are solved to optimality. The paper then proposes a hunting search metaheuristic inspired from group behavior of animals when searching and hunting for food. A set of experimental instances are carried out to evaluate the algorithm. The algorithm is carefully evaluated against the adaptation of two existing algorithms. The results show that the algorithm provides sound performance comparing with other algorithms.