基于生产成本的作业调度

提出了一个基于净现值的调度指标，该指标充分考虑到影响调度决策的各项费用．如在制品库存费用、机床工时费、直接工人的工资、工件提前或拖期完工造成的损失等。然后以遗传算法为工具，研究了作业调度问题，设计了一种很实用的算法。该算法采用基于工序的编码方法把调度编码成染色体，并通过遗传操作来搜索最佳染色体。解码算法根据工序在染色体中的次序和最短加工时间一紧迫度规则得到调度。仿真结果表明该方法是可行的。并有一定的优越性。

Job Shop Scheduling for Decreasing Production Costs

Performance measures of the job-shop scheduling based o n net present value is presented. The main costs (such as costs of work in progr ess inventory, processing costs, worker earnings, and costs of ahead of due dates or missed due dates, etc.) in a scheduling decision are involved. Then a robust pr o cedure based on genetic algorithms for job-shop optimization is developed. In t he procedure, operation-based representation encodes a schedule as a sequence o f operations, and the genetic algorithm is used to derive the optimal chromos ome. The decoding method turns the chromosome into the schedule by the order of operation in the chromosome and SPT-C/T heuristic. An example of the schedulin g is given and it is proven that the method is feasible and efficient.