Joint Stowage and Crane Planning Decision for Steel Products

Ship stowage planning and quay crane scheduling are the main stages that affect the efficiency of steel ship operation on the terminal side. In previous studies, the two stages of optimization are separated. In this paper, a joint optimization model of mixed integer programming is established. By optimizing the stowage planning of steel products at the same time and the sequence of the crane scheduling, the makespan of the ship operation is reduced. For the joint optimization, we first propose the pregrouping of various types of steel products and the stacking of cargo groups. Then we regard the ship's cabin as the operation task of quay crane. In the solution, we propose a formula based on one-dimensional loading to linearize the limit of cabin space capacity and use the number of rows to represent the length of the cargo stack in the cabin, which is simplified as line segment. Finally, the commercial solver CPLEX is used to solve the joint optimization model. Numerical experiments show that the proposed joint optimization model is effective in solving practical problems of steel ship operation compared with the previous phased optimization.