The problem of sequencing ships for a berth was considered where tidal constraints restrict the movement of ships in and out of the berth. However, there is no restriction on berth loading/unloading operations even when there is a low tide. The objective is to sequence the ships, with not necessarily identical processing times, so that the completion time of the last ship's operation can be minimised. We show that the problem is NP-hard and provide some numerical results based on an integer programming approach to the problem.
Paper presented at 'Recent advances in operations research', a mini-conference hosted by the Melbourne chapter of the Australian Society for Operation Research (ASOR), Melbourne, Victoria, Australia, 12 November 2003