廠商為了達到利潤最大，在產品收入方面，利用行銷的手法增加其收入，如廠商的訂價方式依存貨水準來判定，存貨量過高時，廠商為了減少過多的存貨量，必須降價銷售來吸引消費。在生產成本方面，除了必要的設置成本、成品成本和維修成本之外，利用控制存貨成本來降低總成本。因此，廠商要如何控制機器關機時間，來衡量存貨量使能夠達到收支平衡且利潤最大，是目前所有企業的目標。
    在產品方面，存貨物品的退化是常有的現象，其中如環境的因素或其它像潮溼、溫度等等，會導致退化或腐敗，使得存貨數量變少或產品品質降低，廠商為了增加利潤，所以必須要投資改善環境以降低退化率。此時，投資的成本越多，退化率改善的越多，收入會增加，若投資的成本越少，退化率改善的越少，收入會越少。所以不管退化率的改善多寡，收入與成本間呈現對立情形。廠商一方面要如何控制機器關機時間，一方面也要決策投資多少來改善退化率，才能使得利潤達到最大。
    本論文模型將分別於第二、三章探討。第二章將討論如何決策最適機器關機的時間在惡化性的生產系統，使得利潤達到最大。第三章則延續第二章的模型，並假設退化率可因投資改善，要如何決策作最適機器關機時間與改善退化率，使得利潤達到最大。
關鍵詞：價格、需求、存貨水準、退化率、利潤

For the purpose of making maximum profit, it needs to use marketing strategies to increase revenue in the product revenue. For example the manufactures may set the price on the basis of the amount of the inventory, since lower price would decrease the amount of the inventory when it exceed some amount. The manufactures naturally try to reduce the total cost by controlling the inventory cost in the product cost. This leads to make the manufactures to consider how to control the working time of producing machine based on the amount of the inventory which for the final purpose for all of the business.
    The deteriorating phenomenon of the occurs in inventory product. For instance, humidity and temperature, often accelerates deterioration of product in warehouse, and which surely decreases the quality of product lower. To present such occasion, manufactures may invest to improve conditions of its environment. Therefore, the more invest the more improvement of environment and this deteriorating and for more revenue. No matter how much the improvement for deteriorating rate, there exists of the problem that is revenue and cost are opposed to each other. The manufactures in one way need to control the working time of the machine, and on the other hand they need to decide how much to invest for improving deteriorating rate, so that maximum profit can he reached.
    The models are respectively studied for different situation in chapter two and chapter three. On chapter two we discuss how to decide the optimal duration of time for working machine in the deteriorating production system. The model is continued in chapter three for the problem of improving deteriorating rate, decides the determination of optimal duration time of working machine.

目 錄
                                                      頁碼
表目錄..................................................Ⅲ
圖目錄..................................................Ⅳ
使用符號表..............................................Ⅴ
基本架設................................................Ⅵ
第一章  序 論...........................................1
  1.1 研究動機與目標....................................1
  1.2 文獻探討..........................................2
  1.3 研究方法..........................................4
  1.4 研究架構..........................................5
第二章  產品退化下價格需求與存貨水準相關之EMQ模型....7
  2.1 前言..............................................7
  2.2 模型的建立........................................8
  2.3 產品收入之計算....................................12
  2.4 產品成本之計算....................................13
  2.5 產品利潤之計算....................................18
  2.6 模型求解..........................................19
  2.7 數值範例..........................................22
  2.8 敏感度分析........................................24

第三章  產品退化下價格需求與存貨水準相關且能控制退化率之
        EMQ模型.........................................29
  3.1 前言..............................................29
  3.2 使用符號與基本假設................................30
  3.3 模型的建立........................................31
  3.4 產品收入之計算....................................32
  3.5 產品成本之計算....................................32
  3.6 產品利潤之計算....................................35
  3.7 模型求解..........................................36
  3.8 數值範例..........................................38
  3.9 敏感度分析........................................40
第四章  結論及後續研究方向..............................43
  4.1 結論..............................................43
  4.2 未來研究方向......................................44
參考文獻................................................46

                      表 目 錄

表2.1參數值的變動對最適解的影響........................25
表3.1在可改善退化率下，參數值的變動對最適解的影響......40

                      圖 目 錄

圖1.1  研究流程圖......................................6
圖2.1  存貨水準圖形....................................8
圖2.2  產品未退化下的存貨圖形..........................15
圖2.3  產品退化下的存貨圖形............................15
圖2.4   ...........................................20
圖2.5   ...........................................20
圖2.5  模型一範例圖形..................................24
圖3.1  模型二範例圖形..................................39

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