Modeling To Ship-stowage Logistics Planning Of Finished Steel Coils And Its System Development

Product cost in iron & steel enterprises mainly depends on raw material cost, manufacturing cost and logistics cost. Nowadays, the supply shortage and price rising of international raw materials causes high product cost and low profit. The traditional methods to decrease product cost of enterprises focus on reduction of manufacturing cost by improving technology and process. But it is hard to continue reducing when manufacturing cost decreases to a certain degree. Therefore, reduction of logistics cost becomes the main focus of competition among steel enterprises in these years.This paper carries out deep investigation and research on ship-stowage logistics planning of finished steel coils in iron & steel enterprises. Ship-stowage logistics planning is to determine suitable coils for the ship whose information has been given, considering destination, storage position, weight, and size of coils. This paper is to perform the research as follow:(1) According to actual situation and characters of ship-stowage logistics planning, a mathematical programming model is established. It is mainly desired to maximize ship loading ratio, simultaneously considering direct stowage priority, due date priority, contract status priority and so on. And this problem has two constraints: the plan mustn't exceed the ship's rated weight; the same ready bill in direct loading way must be selected into plan at the same time.(2) Tabu search algorithm is adopted to solve the problem. The initial feasible solution of tabu is generated by a heuristic algorithm depending on stowage operational Know-how. And we separately adopt swap neighborhood and variable depth neighborhood. The computational results based on a set of actual data are better than manual work greatly. Especially the solution obtained by hybrid algorithm of tabu search and variable depth search in practical time is most competitive.(3) In order to apply the theoretical results to practical stowage, this paper develops a decision support system for ship stowage in iron & steel enterprises in which the proposed model was used as an effective method to optimize loading planning. The application of this system will realize optimal auto-stowage, improve the efficiency of stowage and reduce logistics costs.