Berth Assignment Scheduling for Shipment by Branch and Bound Method with Estimating-Cost Search

In this paper, we describe a scheduling algorithm for berth assignment of shipment in iron and steel works. In the berth scheduling we discuss here, it is necessary to consider both minimization of the waiting-time of shipment for each ship and maximization of the efficiency of work in each berth. To determine the optimal combination between berths and ships, and the optimal order of shipment, we develop an algorithm based on branch and bound method. To improve the efficiency of optimal solution search in this algorithm, we introduce an estimation term of cost-increase for unallocated ships in the evaluation function structure, and use a heuristic search in determination of an initial solution. Moreover, to apply to a larger problem, we also use a practical solving method for divided search space. By using this algorithm, the scheduling system can provide a useful planning result of daily berth assignment within practicable time.