- 學位論文
多站生產系統之等候模式分析
Performance Analysis of Multi-Station MTO/MTS Production System
摘要
在日益競爭的環境下，製造業廠商降低商品價格以維持競爭力，在低價化的影響之下，製造業廠商必須降低成本以提高利潤，國際上的製造業廠商也不斷的尋找或是研究生產模式來降低成本提高獲利空間。然而製造商在生產產品的過程中必須向上游的供應商訂購所需之原料或是產品的半成品，然而顧客需求是隨機出現，當需求增加時可能造成生產系統的產品或是原料短缺，此情況往往是一般製造商較為困擾之問題，且可能導致顧客需求等候時間增加或是顧客流失，因此製造商必須尋求新的生產策略來盡可能即時滿足顧客需求同時不使生產成本提高。基於上述原因，等候線網路問題之於製造業廠商改善生產模式顯得相對重要；等候線網路系統可以用來定義、建構類似的生產系統，利用數學方法求得系統平均數量、分析重要的績效指標，使生產系統在績效指標達到預期標準的條件下成本最佳化。 本研究在上述動機下，探討串聯式多站庫存等候系統中的需求回應時間以及Fill rate，此系統是上游串連多個工作站以訂單式生產方式生產半成品提供下游工作站所訂購之需求，而下游最終工作站是以存貨式生產並以基本庫存量策略來控制庫存；本研究利用數學方法求得需求回應時間以及Fill rate，在考慮成本的條件下，找到最佳的庫存量。
並列摘要
Under the environment of the competitive market, manufactures cut down the product prices to maintain the good competitiveness in global market. As above, manufactures have to reduce production cost to increase their profit. Global manufactures are looking for the new production system or try improving production system constantly for increasing the profit. Manufactures order materials or semi-finished products from suppliers. But demands arrival is randomly, production system may be lack of products when demands increasing. In this case, Manufactures would get in a troubles regarding the shortage problem. Because it may let the customers to increase their waiting time and this also causes the time and sales loss at customer's side. Therefore, manufactures need to seek for new production strategy for satisfying demands and minimizing production cost. Based on the above points, the inventory-queueing system which is an important model for the manufactures. We can imitate similar production system by using Queueing Theory, also we utilize the mathematical quantification to analyze and optimize the important appraisal targets. In this study, we consider a tandem as a model of multistage production system in which the downstream is a Make-to-Stock(MTS) system and the upstream is a series of Make-to-Order(MTO) system. In this system, the MTS system is controlled under the base-stock policy. This system is analysis the waiting time and fill rate of the demand. We use mathematical methods to evaluate the corresponding performances. Furthermore, we can set cost structure and find out the optimize base-stock level.