Quay Crane Scheduling In Port Container Terminals: Mathematical Model And Solution Algorithm

As the throughput of Chinese port container terminals increases rapidly, how to enlarge the capacity of Chinese port container terminals is an immediate challenge that port operators confront. There are two methods for solving this problem: the first one is to construct more port container terminals as soon as possible, but it needs huge money and long time period; the second one is to enhance the efficiency of port container terminals. Quay cranes are the interface between water side and land side in any port container terminal, and thus their efficiency affects the efficiency of port container terminals significantly. This research focuses on quay crane scheduling problem to improve their efficiency.Based on the investigation into Shenzhen international container terminal and literature review, this research provides a mathematical model for the quay crane scheduling problem considering non-crossing and safety distance constraints. Furthermore, this research proves that the proposed quay crane scheduling problem is NP-complete, which means there exists no polynomial time algorithm for the exact solution. This research, therefore, develops a genetic algorithm to obtain near optimal solutions. Six random instances with small sizes and thirty ones with large sizes are conducted to evaluate the performance of the proposed model and genetic algorithm. Computational results show that the genetic algorithm is effective and efficient in solving this quay crane scheduling problem. Compared with the current quay crane scheduling method in port container terminals, the genetic algorithm enhances the efficiency of quay crane scheduling about 10%. The proposed genetic algorithm can be considered as an appropriate approach to scheduling quay cranes instead of the current method in port container terminals.