多批量下料問題在中斷式幾何分配且有限設置次數及庫存成本下之研究

Lot Sizing Problem With the Interrupted Geometric Yield,Finite Setup and Holding Costs

謝偉志(Wei-Chih Shie)

指導教授 ： 古 思 明 博士 ； 徐 旭 昇 博士

元智大學/工程學院/工業工程與管理學系/碩士(2000年)

摘要

摘要
綜觀之前最小成本之生產批量問題，皆將著眼點放在最適下料量，而忽略時間因素及庫存成本，而這並非是目前製造工廠之生產線實際面對的情形，因此本文特將此兩項因素列入考量，使之更符合實際之情形。
在機器為中斷式幾何生產分配，且成本是線性函數情形下之數據模擬，可得知結論如下：(1)生產成本與機器良率成反比(2)生產期具有連續性及延製性(3)最適下料量會收斂(4)設置次數會收斂(5)懲罰成本與機器良率對下料量成同向增減(6)庫存成本愈高下料期數愈短。在知道這些特性後，對於我們面對顧客的訂單時，可以對生產有更明確之掌握。

關鍵字

最佳批量 ； 中斷式幾何生產分配 ； 動態系統

並列摘要

Abstract
In the existing literature regarding to the multiple lot-sizing problems with random yield, two practical issues: finite number of setups and holding costs seems to be ignored for study. In this thesis, we shall impose these two factors into the model to derive some managerial insights.
Assume that the random yield follows an interrupted geometric distribution and the cost structure is linear, various numerical simulations allow us to obtain the following managerial insights. (1) Improving the yield rate will reduce the production cost.
(2)Production periods are consecutive and are implemented as late as possible.
(3) The optimal lot sizes will converge as the customers’ demands become large.
(4) Numbers of setups will converge.
(5) Penalty costs and the yield rates have the same effects over the optimal lot sizes.
(6) The higher the inventory costs are, the shorter the production periods will be.

並列關鍵字

optimal lot-size ； geometric distribution ； dynamic program