在含缺貨欠撥和可能重工失敗的生產模式探討不良品重工與否之決策

To rework or to scrap the defective items in EPQ model with backlogging and failure in rework - A decision-making process

楊東洲(Dong-Chou Yang)

指導教授 ： 邱元錫

朝陽科技大學/理工學院/工業工程與管理系/碩士(2010年)

摘要

本研究探討在不完美品質生產系統下，含重工與否之生產決策與成本效益分析。傳統經濟生產批量大都假設生產系統都是完美的，但實際上的生產系統並非想像中的完美，隨著機器使用時間越久，機器設備的狀況也會比較不穩定，且機器當機的機率也會提升，或者其他因素造成變異，難免都會生產出部份不符合品質標準的產品。一般而言，不良品的處理方式有兩種：一是嘗試重工修復，二是視為報廢品處理。當企業決定將不良品報廢時，就需額外負擔報廢成本；決定將不良品重工修復時，就需額外付出重工修復時的持有成本與加工成本。
本研究針對二個不良品產出後不同的處置假設之存貨模式做決策分析，包含(1)不完美品質生產系統且在允許缺貨模式下，不良品採「重工修復」之決策分析(2)不完美品質生產系統且在允許缺貨模式下，不良品皆視為「全部報廢」之決策分析。探討在已知的條件下，藉由本研究所建構推導出之數學判斷式，決定應採用何種最佳存貨生產模式，使其總生產成本最符合經濟效益，最後提出實例驗證，並對其參數作敏感度分析，作為企業界實際應用與決策制定上之參考依據。

關鍵字

不完全品質 ； 重工修復 ； 經濟生產批量模式 ； 報廢品

並列摘要

This study considers imperfect quality product system whether rework or scrap on product policy and analyze cost efficiency. One of the unrealistic assumptions of classic Economic Production Quantity(EPQ) model is that it assumes manufacturing facility functions perfectly all the times. However, in most practical settings, due to process
deterioration or the other factors, defective items are generated. The imperfect quality items can fall into two groups, the repairable and the scrap. When the company decided to scrap defective items, need to pay the extra scrap costs. And sometimes, the imperfect quality items can be reworked and repaired with additional repairing and holding costs.
Two specific models are considered to make a decision analysis for different inventory situations in this study. They are situations where：(1)the imperfect quality system in an EPQ model with backlogging permitted, and all defective items are reworked and can be repaired;(2)the imperfect quality system in an EPQ model with backlogging permitted, and all defective items are scrap. Under the situations that have already known, this study proposes a mathematics judgment type on EPQ model with scrap and rework defective items and derived the optimal inventory product model and backordering level that minimize overall production costs. Finally, numerical example is provided to demonstrate their practical usages.

並列關鍵字

rework ； imperfect quality ； scrap ； EPQ model

參考文獻

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