【作者】 蔡晨； 汪玲；

【Author】 Cai Chen & Wang Ling(Institute of Policy and Management, CAS, Beijing 100080)

【机构】 中国科学院科技政策与管理科学研究所；

【摘要】 单件车间(或称工艺导型工作环境)是产出品种多,数量少,按定货来制造产品的生产系统。该系统生产的各种产品在使用的物料,操作要求,操作时间以及生产准备要求等方面有很大的差异,在交货期和企业有限资源约束下。寻求最优排程十分困难。即使对非常简化了的作业程序,理论上也是NP-hard问题,没有好的算法能够找到最优解。因此,许多有关排程的研究都放弃追求最优解,而将目标转向于排程技巧,其中利用优先准则的方法最为常见。然而,现有的这些启发式准则又过分限制了搜索接近最优解法机会。为了弥补这一不足之处,ARAKAWrA等人提出了一种以模拟为基础的排程方法。在本文中,我们进一步采取在平均工作延迟时间标准上效果较好的关键比率准则(Critical-ratio),并引进前向松驰与后向松驰两个时间参数来调整原来的松驰时间,从而改变CR值,使本来由关键比率准则只能产生一个方案变成可以生成多个方案,从而增加了接近最优解的机会。试验结果表明,本文提出的模拟方法对最小化到期日偏差来说,可以收到更好的效果。更多还原

【Abstract】 Job shop, also called job focus, is a production system that has lots of types, small scales, and make-for-order products. There are much differences in the materials, operation requirements, operation time, and preliminary conditions in producing among all the products generated in the system. It is very hard to find the optimal schedule under the resource constraints. Theoretically, it is an NP-hard problem even for the simplified scheduling. Hence, some researchers discussed the scheduling methods instead of searching the optimal schedule, which commonly apply the priority rule. However, these rules reduced the chance that we obtain the optimal plan. In order to improve it, Arakawa et al proposed a Simulation-job-delay-time, the critical-ratio rule, together with two parameters for adjusting the forward slack and the backward slack to change the value of CR. It increases the probability of approximating the optimal schedule among the several schedules generated by using the CR rule. It is proved that the method proposed in this paper is more efficient in minimizing due-date deviation.更多还原