热轧钢管主生产计划模型与算法研究

Model and algorithm for hot rolling steel tube MPS

建立了热轧无缝钢管主生产计划问题的混合整数线性规划模型.该模型可归结为多阶段多产品带有能力约束的批量问题,但与传统批量问题存在以下不同:①充分反映了钢管企业与其它行业的不同工艺特点;②目标函数追求最大化现金流而不是最小化成本;③允许订单积压;④考虑库存能力约束;⑤忽略设置时间及成本,但引入了最小生产批量约束.鉴于该问题的NP难性,使用两种基于优化的启发式算法进行求解,并提出两条策略加以改进.

The master production scheduling （MIXS） problem of hot rolling seamless steel tube is formulated as a mixed integer linear programming model. The model fits into the class of multi-stage multi-item capacitated lot sizing problem, however, compared with traditional similar problems, there are several differences： ① The model is based on the characteristics of steel tube production process, which is distinct from other industries; ②The model＇ s objective is to maximizing the cash flow instead of minimizing the total cost; ③ Backorder is introduced; ④ Inventory constraints are considered; ⑤ Setup time and setup cost are ignored, however some setup variables are introduced to satisfy the constraints on minimum lot-sizes. Considering the problem is of NP-hard, two effective optimization-based heuristic algorithms are suggested. Before using the two algorithms, two strategies are presented to improve their efficiency.