A flexible crane scheduling methodology for container terminals

In this paper, we propose a flexible neighbourhood search strategy for quay crane scheduling problems based on the framework of tabu search (TS) algorithm. In the literature, the container workload of a ship is partitioned into a number of fixed jobs to deal with the complexity of the problem. In this paper, we propose flexible jobs which are dynamically changed by TS throughout the search process to eliminate the impact of fixed jobs on the generated schedules. Alternative job sequences are investigated for quay cranes and a new quay crane dispatching policy is developed to generate schedules. Computational experiments conducted with problem instances available in the literature showed that our algorithm is capable of generating quality schedules for quay crane handling operations at reasonable times.