考量多物項多產品下二階存貨策略之模擬研究

Simulation study on two-stage inventory policies with multiple items

張瑜真(Yu-Jen Chang)

指導教授 ： 蔡啟揚

元智大學/工程學院/工業工程與管理學系/碩士(2005年)

摘要

在存貨管理上，如何降低缺貨發生，降低系統總成本，是提高系統績效的重要課題。本研究考慮一二階存貨模型，此模型是由上下游兩個存貨系統所組成的。而這兩階段的存貨系統的存貨量具有相依關係，也就是說下游的產品製造是需要提取上游的物項存量而來的，並且在此系統架構下，該生產型態為由多種的原物料項生產出多種的半成品或成品，也就是說此系統又包含了多物項的關係。因此，若要有效管理存貨來提高系統績效，勢必需要考慮此系統之多物項關係與二階存貨系統下的物項相依關係。
因此本研究將針對上述之二階存貨系統，提出同時考量二階存貨系統的協同存貨策略，此策略考量了二階存貨系統中的多物項特性與物項間相依性，並以服務水準、相關成本等績效指標與其他策略進行策略比較。再利用變動顧客的需求、需求的變異係數、前置時間平均與前置時間變異係數做系統的模擬研究，分析導入各策略對系統的績效影響以及各策略在表現上的差異與趨勢。最後從比較中顯示所提之協同存貨策略能改善存貨系統的總成本，因此協同策略可提供改善二階存貨系統績效的參考。

關鍵字

二階存貨系統 ； 多物項 ； 模擬 ； ( s,S )存貨策略

並列摘要

In the inventory management, in order to increase the performance of the system, reducing the supply shortage and total cost of the system are the important issues. This research considers a two-level inventory simulation model which is composed of two inventory stages, raw materials and finished goods (semi-products).
In the two phases of the inventory system, the quantity of inventory has dependent relationship. In other words, the manufacturing of products at the second stage needs the inventoried materials at the first stage. In addition, multiple products/semi-products and multiple items at the two stages are considered.Therefore, in order to increase the effectiveness of the inventory management of such systems, It is necessary to consider the properties of multiple items and the dependent relationship between the inventories of the two stages.
In accordance with the system, this research focuses on the two-level inventory model and proposes a strategy that takes into consideration the interrelationship between the two stages as well as among the item. The proposed policy is compared with other policies based on performance indexes which include the service level and related costs. Furthermore, sensitivity analysis is conducted on system parameters, including the customer demand, the coefficient of variation of demand, the average lead time and the coefficient of variation of lead time. It also discusses the influences and differences of the various strategies on system performance. Finally, according to the analysis, it can be shown that the proposed strategy can improve the performance of an inventory system.

並列關鍵字

Two-level inventory system ； simulation model ； multiple items ； simulation ； ( s , S ) inventory policy

參考文獻

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