Abstract
當生產系統尚處於引入學習及時化生產方式的階段時 ，系統中各站仍存在著一些失效因子，例如：機器的故障、刀具的損壞、操作的失誤、製程的不良等等。這些失效因子的發生會導致某站產能突然降低一段時間。若在某一裝配站需由前面各站供應零組件的情況之下，各站失效因子的發生對系統績效的影響將更嚴重。因此，上述情況的生產系統可能必須權衡底下兩方面的問題。一方面它必須為顧客提供一定的服務水準；另一方面它必須使用看板系統來降低在製品存貨水準以進行改善活動。本研究的目的就是要發展一套動態式控制方法。此套方法不僅可讓各站尚存有失效因子的多線及時化生產系統達到一定的績效水準，同時亦可輔助此一系統進行改善活動。其系統績效的衡量指標是遲交需求個數的平均百分比。至於達到某一預定系統績效的手段則是在於同時控制各站的看板數及加速生產政策。此外，在本文中將利用模擬工具來舉例說明本套方法如何使用。文中亦展示此套方法在及時化生產系統的改善過程中所扮演的角色。最後，本套方法將加以擴充其適用範圍。During the implementation stage of a Just-In- Time (JIT)production system, stage failures, such as machinebreakdowns, tool failures, operator errors, in-processdefects, and etc., may cause the loss of capacity in a timeperiod at a stage. The effect is even more serious if oneassembly stage is fed by several stages. Therefore, such asystem may face the following trade-off problem. On onehand, it must maintain a certain level of service rate forcustomers, On the other hand, it needs to carry onimprovement activities by using the Kanban system to reducethe work-in-process level. The purpose of this study isto develop a dynamic control method (DCM) for meetinga predetermined level of performance of a multi-line JITsystem and assisting improvement activities for a systemwhich is still experiencing stage failures. The performanceis measured by the average percentage of the number ofbacklogged demands. The key of this method is to controlboth the number of Kanban cards and the rush productionpolicy at each stage. This method is also illustrated byusing simulation examples. In addition, the assistance roleof the DCM in the improvement process of a JIT system isshown. Finally, some extensions for this method arediscussed.