Modeling And Optimization For The Ship Consolidation And Stowage Planning Of Steel Product

Logistics can be classified by different way. By function it can be classified as production logistics and transportation logistics. By operation, it can be classified as transportation, storage, carry and stowage. By transportation method, it can be classified as ship, rail, truck and air transportation. The logistics of iron and steel enterprises belongs to typical production logistics. Nowadays the extensive management mode replied on the manual planning of logistics cannot satisfy the demand of logistics complex optimization of products, due to the large monomer weight, multiple breed and shape, high requirement of surface quality and big transport capacity of steel products. Therefore, how to anpplying fine management for logistics operation process, reduce the logistics cost, develop the utilization of logistics equipment and satisfy the customers becomes the important and necessary issues of the steel enterprises. In this dissertation, the ship consolidation and stowage planning problems of steel industry are researched.For solving the ship consolidation planning and stowage planning problem, integer linear programming models are proposed in this dissertation. And according to the theoretical analysis of the problem, the intelligent optimization algorithms are developed to approximately solve the problems due to the NP-hardness characteristics of solving model. Finally a decision support system is developed to apply the practical application. The main contents are summarized as follows.(1) The purpose of ship consolidation planning problem of steel product is to select the suitable steel products for a given ship according to the information of coils, maximize the weighted sum of incentive cost of load of the ship, and penalty cost of shuffling number of the steel products and the penalty cost of the number of splitting contract. The total weight of the selected products cannot exceed the rated loading capacity of the ship. By taking the relationship of the assignment between coils and ship as the decision variable of the model, the shuffling number is figured out and an integer linear programming model is proposed. The model can be solved by CPLEX for small scale problems.(2) According to the NP-hardness characteristics of solving consolidation planning problem model, a hybrid intelligent optimization method of scatter search and variable depth search algorithms is developed. In this algorithm, the initial populations are obtained by the heuristic and are improved by the variable depth search algorithm for updating the reference set. The test results prove the effectiveness of the algorithm.(3) The ship stowage planning problem of steel product is to assign the selected steel coils to the ship and figure out the coordinates of the coils, by considering the requirement of ship balance and stowage operation constraints. The objective is to keep the balance of the ship during the voyage, minimize the unloading shuffling and dispersion of the coils of same destination on the ship. The constraints are the balance requirement of ship and stowage specification. Taking into account the difficulty of describing the stability of ship, a new calculating method of orthogonal moment is proposed to describe the measure of two-dimensional balance of ship. Based on the method, an integer linear programming model is proposed. The model can be solved by CPLEX for small scale problems.(4) According to the research of the stowage planning problem, a tabu search algorithm is developed to approximately solve the problem. In the algorithm, a heuristic is proposed according to the manual planning method. Analysis of optimal property of the problem, an accelerating strategy of tabu search and the multi-neighborhood are proposed to improve the performance of the algorithm. For large scale problem, a lower bound based on the relaxed model is proposed. The tests with random and practical data validate the effectiveness of the algorithm.(5) According to the ship consolidation and stowage planning problem of steel products, a decision support system is developed based on the above models and algorithms. It realizes several functions such as the automatic generation of plan, graphic display, and index evaluation, manual editing. The proposed models and algorithms are test by the practical data.