A Study of Flexibility on Manufacturing System-An Operations Research Approach

本课题研究了柔性制造系统（FMSs）等现代自动化制造系统的柔性对其规划和控制的影响。特别是，详细分析了灵活性对调度和调度优化的影响，以及由于机器的灵活性而减少作业次数的影响。主要研究结果如下：(1)FMS调度规则的性能评价利用详细的FMS模拟器对FMS调度规则的性能进行了分析。将物料自动搬运装置、有限数量的托盘、有限尺寸的缓冲料等因素纳入模型，并对其影响进行了分析。结果表明，在不存在路由灵活性的情况下，基于处理时间的简单（但新的）调度规则具有良好的性能。(2)利用“协同调度”的灵活性传统调度规则没有充分利用FMSs的路由灵活性这一关键特性。为了最大限度地利用路由的灵活性，提出了一种新的协同调度方案。大量的仿真研究表明，作业和机器之间的合作导致了交货日期满意度、机器利用率和作业流程时间等性能指标的改善。(3) FMS调度优化

This research project studied the effects of flexibility of modern automated manufacturing systems such as flexible manufacturing systems (FMSs) on their planning and control. In particular, the effects of flexibility on dispatching and schedule optimization have been analyzed in detail together with the effects of the reduction of the number of operations due to flexibility of machines.Main results are summarized below :(1) performance evaluation of dispatching rules in FMSPerformance of dispatching rules in FMS has been analyzed using detailed FMS simulator. Such factors as automatic material handling devices, finite number of pallets, finite size of buffer are included in the model, and their effects analyzed. The results show that processing-time-based simple (but new) dispatching rules give good performance when there exist no routing flexibility.(2) "cooperative dispatching" to exploit flexibilityAs routing flexibility, which is one o the key characteristics of FMSs, is not fully exploited under the traditional dispatching rules. To best utilize routing flexibility, a new scheme called Cooperative Dispatching has been proposed. Extensive simulation study shows that the cooperation between jobs and machines lead to improvement in performance measures such as due-date satisfaction, machine utilization, and job flow time.(3) optimization of dispatching in FMS