Ship-unloading scheduling optimization with differential evolution

This study aims at investigating a scheduling problem for unloading of material ships in a large-scale steel plant. The optimization problem minimizes the cost caused by improperly delayed unloading operations of the ships for a given time horizon. The problem intends to decide the order of unloading ships and the allocation of conveyors to the ships. The solution for the practical-sized problem is NP-hard because of the dimensionality of the problem. In this paper we resolve the problem using a well-designed differential evolution algorithm (DE). In addition, a mathematical programming model is given as well for comparison. An empirical study with some comparative results from CPLXE solver and other DE variants is carried out, which shows a good potential for real-world applications.