上游MTS生產及下游MTO生產之庫存等候系統

The Inventory-Queue System Consisting of the Upstream MTS Production and the Downstream MTO Production

邱議德(Yi-Der Chiou)

指導教授 ： 張國華

中原大學/工學院/工業工程研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700431

摘要

摘要
等候線網路問題對於製造業日益重要，原因是國際上的製造業廠商已經面臨許多生產製造上面的問題，加上低價化潮流之下，國際大廠爲了降低成本以提高利潤，都不斷的找尋及研究生產模式來降低成本以創造獲利的空間。不例外的台灣的製造業也面臨同樣的問題。例如：台灣的筆記型電腦組裝業，在生產製程上就會碰到一些問題，像是在生產過程中先MTS生產方式以滿足一般需求，但是在競爭激烈的環境中與顧客多樣化的需求之下，使得廠商面臨不得不尋求方法來滿足顧客需求之外，還要不使生產成本提高的先決條件，才能提昇產業競爭力。但往往客製化需求相較於一般需求較為製造業所困擾，原因為客製化需求較不穩定、需求量較一般需求小很多且要即時滿足顧客。所以許多製造業在接受客製化需求時，投入許多人力與資源以滿足顧客需求，而當需求少時則造成人力與資源的浪費。所以等候線網路系統可以運用數學方法的去求得系統平均數量、分析並且最佳化重要的績效指標。現今等候線系統在製造業已被廣泛的使用與持續的分析改進新系統。例如：在全球供應鏈中運用庫存等候線系統應用在產品庫存與組裝生產過程。

本研究在上述動機之下，探討一個兩站庫存等候線系統中的需求回應時間，其中此系統是上游工作站以MTS的生產方式生產庫存供應下游MTO工作站，當客製化需求到達此系統時，會直接由上游工作站以MTS方式生產的庫存取貨到下游MTO工作站中加工，以此生產方式下可減少上游工作站加工時間，將半成品直接送至下游工作站加工以達到減少顧客等候時間，而上游工作站生產是以基本庫存量策略來控制庫存。

本模式研究是以幾何矩陣的數學方法求得穩態機率後，可推得平均需求回應時間與平均需求等候個數，此外最後模式中考慮成本因素下，我們可決定基本庫存水準不但使得生產總成本為最低，且又可達到減少需求回應時間的目的。

關鍵字

Matrix-geometric ； 基本庫存量策略 ； 庫存等候線系統 ； MTO/MTS 生產系統

並列摘要

Abstract
The queueing networks are the important models for the multiprogrammed and time-shared computer systems. Because of queueing system can describe the production, manufacture, communication, and computer network and service system. Also we utilize the mathematical quantification to model, analyze and optimize the important appraisal targets. Right now, the queueing system is kept applying and analyzing to improve new system, such as the inventory queueing system utilized in the global supply chain of consumer products and the queueing system applied in the assembly manufacturing (such as laptop computers). Assembler, in addition to fulfill the ordinary orders for the regular product by adopting Make-to-Stock (MTS) production, they are often asked to take care the special demands for the customized products by adopting Make-to-Order (MTO) production.

In this model, we consider a two-station system in which the first station is a MTS system supporting the semi-products to be used at the second station which performs the follow-up process to the special demands. In this system, the MTS systems are controlled under the base-stock policy. The system is analyzed the response time of the demand in a two-station inventory-queue system, which is used to describe a serial supply chain system with MTO stochastic demands. We consider the base stock policy for accelerating the response to the demand. The limiting probabilities are obtained by using matrix-geometric approach and their corresponding performances under base-stick control policy can also be obtained. Furthermore, we can determine the optimal base-stock level numerically.

並列關鍵字

inventory-queue system ； matrix-geometric ； base-stock policy ； MTO/MTS production

參考文獻

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