存貨管理一直是企業經營中相當重要和關鍵性的因素。而在過去關於存貨管理的研究中大都假設生產過程完備，所產出的產品皆為良品。但實務上，由於機器設備老舊或人為操作失當等，都會導致產生不良品。
　　此外，供應商為了提高市場競爭力，通常願意提供零售商一段允許延遲付款的信用交易期間，在此信用交易期間內零售商不需支付利息，並且可利用已售出貨品的收入產生利息。但在延遲付款期間結束時，付清貨款後，若仍保有存貨，則需負擔資金的積壓成本。
　　本研究探討兩個整合的供應鏈存貨模式，研究供應商如何利用投資資金以降低產品不良率，並且提供零售商信用交易的條件。第二章討論當零售商於指定時間內提早付清貨款即可享有價格折扣；否則，就必須在最後付款期限前將所有貨款付清。第三章討論供應商提供信用交易的條件與零售商的訂購量有關。兩個存貨模式均以單位時間總利潤極大化為目標，分別建立演算法以利求得最適策略。最後，以數值範例說明求解過程，並做敏感度分析以瞭解參數值變動對最適解的影響。

Inventory management is a very important and critical function of the business enterprise. In past, most inventory models run on the assumption that product process is in the normal situation, meaning that all products are all perfect. However, in real production environments, machine might deteriorate and employee might operate machine in the wrong way, it might cause producing defective products.
  On the other hand, the supplier in order to increase market competition is willing to offer the retailer a certain trade credit period without paying interest and can use the sales revenue to earn interest during the trade credit period. When the period is due, and the payment is made, the retailer has to pay interest for the products still in stock.
This thesis develops two integrated supply chain inventory models, it handles the supplier how to reduce the products defective rate by investing capital and offers the retailer trade credit conditions. In chapter 2, we develop an integrated supplier-retail inventory model with the supplier offers the retailer a cash discount if payment is made before a specified period, and if the retailer does not pay within the specified period, the total purchasing costs must be paid before the delay payment due date. In chapter 3, the condition of trade credit depends on retailer’s order quantity is considered. The goal of these integrated inventory models above are to maximize total profit per unit time, and further, this thesis establishes an algorithm to determine the optimal strategy for each model. Finally, numerical examples are provided to show the solution procedure, and the sensitivity analyses are presented to illustrate the effects of the change of the parameter values on optimum solution.

目錄------------------------------------------------------ I
表目錄---------------------------------------------------III
圖目錄----------------------------------------------------IV
使用符號一覽表---------------------------------------------V
基本假設--------------------------------------------------VI
第一章　緒論-----------------------------------------------1
   1.1　研究動機與目的-------------------------------------1
　 1.2　文獻探討-------------------------------------------2
     1.2.1　整合存貨模式-----------------------------------2
     1.2.2　不良品-----------------------------------------3
     1.2.3　信用交易---------------------------------------4
   1.3　研究架構-------------------------------------------6
第二章　供應商投資資金改善產品品質並且提供零售商二選一信用交
　　　　易條件下之整合供應鏈存貨模式-----------------------7
   2.1　前言-----------------------------------------------7
   2.2　符號說明與假設-------------------------------------8
   2.3　模式的建立-----------------------------------------9
     2.3.1　供應商單位時間的總利潤-------------------------9
     2.3.2　零售商單位時間的總利潤------------------------12
     2.3.3　供應鏈單位時間的總利潤------------------------17
   2.4　模式的求解----------------------------------------18
   2.5　數值範例------------------------------------------26
第三章　供應商投資資金改善產品品質並且提供零售商信用交易的條
　　　　件與其訂購量有關之整合供應鏈存貨模式--------------29
   3.1　前言----------------------------------------------29
   3.2　符號說明與假設------------------------------------30
   3.3　模式的建立----------------------------------------30
     3.3.1　供應商單位時間的總利潤------------------------31
     3.3.2　零售商單位時間的總利潤------------------------34
     3.3.3　供應鏈單位時間的總利潤------------------------39
   3.4　模式的求解----------------------------------------42
   3.5　數值範例------------------------------------------59
第四章　結論----------------------------------------------63
   4.1　主要研究成果--------------------------------------63
   4.2　未來研究方向--------------------------------------64
參考文獻--------------------------------------------------66
附錄------------------------------------------------------70

表目錄
表2.1　範例2.1的最適解彙整表------------------------------26
表2.2　範例2.2的最適解彙整表------------------------------27
表2.3　範例2.3的最適解彙整表------------------------------28
表3.1　範例3.1的最適解彙整表------------------------------60
表3.2　範例3.2的最適解彙整表------------------------------60
表3.3　範例3.3的最適解彙整表------------------------------61

圖目錄
圖2.1　供應商的累積存貨水準示意圖-------------------------10
圖2.2　零售商的存貨水準示意圖-----------------------------14
圖2.3　當T≦Mi時，零售商用以計算利息賺得的數量------------15
圖2.4　當T≧Mi時，零售商用以計算利息賺得與支付的數量------16
圖3.1　當T＜Td時，零售商用以計算利息賺得與支付的數量------35
圖3.2　當T≧Td時，零售商用以計算利息賺得與支付的數量------37

[1]　Banerjee, A. (1986). A joint economic-lot-size model for purchaser and vendor. Decision Sciences 17, 292-311.

[2]　Biskup, D., Simons, D. and Jahnke, H. (2003). The effect of capital lockup and customer trade credits on the optimal lot size – a confirmation of the EOQ. Computers & Operations Research 30, 1509-1524.

[3]　Brigham, E. F. (1995). Fundamentals of Financial Management, 7 th edition, Dryden. Press, Orlando, Florida.

[4]　Chang, C. T., Ouyang, L. Y. and Teng, J. T. (2003). An EOQ model for deteriorating items under supplier credits linked to ordering quantity. Applied Mathematical Modeling 27(12), 983-996.

[5]　Chang, H. C., Ho, C. H., Ouyang, L. Y. and Su, C. H. (2009). The optimal pricing and ordering policy for an integrated inventory model when trade credit linked to order quantity. Applied Mathematical Modeling 33(7), 2978-2991.

[6]　Chung, K. J., Chen, Y. C. and Lin, S. D. (2011). A two-warehouse inventory model under trade credit in the supply chain management. African Journal of Business Management 5(7), 2625-2643.

[7]　Eroglu, A. and Ozdemir, G. (2007). An economic order quantity model with defective items and shortage. International Journal of Production Economics 106, 544-549.

[8]　Goyal, S. K. (1976). An integrated inventory model for a single supplier-single customer problem. International Journal of Production Research 15(1), 107-111.

[9]　Goyal, S. K. (1985). Economic order quantity under conditions of permissible delay in payment. Journal of the Operational Research Society 36, 335-335.

[10]　Goyal, S. K. (1988). A joint economic-lot-size model for purchaser and vendor: a comment. Decision Sciences 19, 236-241.

[11]　Goyal, S. K. (1995). A one-vendor multi-buyer integrated inventory model: a comment. European Journal of Operational Research 82, 209-210.

[12]　Haley, C. W. and Higgins, R. C. (1973). Inventory policy and trade credit financing. Management Science 20(4), 464-471.

[13]　Hall, R. W. (1983). Zero Inventories, Dow Jones-Irwin, Homewood Illinois.

[14]　Ho, C. H., Ouyang, L. Y. and Su, C. H. (2008). Optimal pricing, shipment and payment policy for an integrated supplier-buyer inventory model with two-part trade credit. European Journal of Operational Research 187(2), 496-510.

[15]　Hsu, W. K. and Yu, H. F. (2010). An EOQ model with imperfective quality items under an announced price increase. Journal of the Chinese Institute of Industrial Engineers 28(1), 34-44.

[16]　Huang, C. K. (2001). An integrated inventory model for supplier and retailer with defective items. Journal of Information & Optimization Sciences 22(3), 509-519.

[17]　Huang, C. K. (2002). An integrated vendor-buyer cooperative inventory model for items with imperfect quality. Production Planning & Control 13(4), 355-361.

[18]　Huang, C. K., Cheng, T. L., Kao, T. C. and Goyal, S. K. (2011). An integrated inventory model involving manufacturing setup cost reduction in compound Poisson process. International Journal of Production Research 49(4), 1219-1228.

[19]　Huang, Y. F. (2003). Optimal retailer’s ordering policies in the EOQ model under trade credit financing. Journal of the Operational Research Society 54, 1011-1015.

[20]　Huang, Y. F. (2007). Economic order quantity under conditionally permissible delay in payment. European Journal of Operational Research 176, 911-924.

[21]　Huang, Y. F. and Chung, K. J. (2003). Optimal replenishment and payment policies in the EOQ model under cash discount and trade credit. Asia-Pacific Journal of Operational Research 20, 177-190.

[22]　Ouyang, L. Y. and Chang, H. C. (2000). Impact of investing in quality improvement on (Q,r,L) model involving imperfect production process. Production Planning and Control 11, 598-607.

[23]　Ouyang, L. Y., Chang, H. C. and Chen, C. K. (2002). Quality improvement, setup cost and lead-time reductions in lot size reorder point models with an imperfect production process. Computers & Operations Research 29, 1701-1717.

[24]　Ouyang, L. Y., Ho, C. H. and Su, C. H. (2008). Optimal strategy for an integrated system with variable production rate when the freight rate and trade credit are both linked to the order quantity. International Journal of Production Economics 115(1), 151-162.

[25]　Ouyang, L. Y., Ho, C. H. and Su, C. H. (2009). An optimization approach for joint pricing and ordering problem in an integrated inventory system with order-size dependent trade credit. Computers & Industrial Engineering 57(3), 920-930.

[26]　Ouyang, L. Y., Wu, K. S. and Ho, C. H. (2006). The single-vendor single-buyer integrated inventory problem with quality improvement and lead time reduction – minimax distribution-free approach. Asia-Pacific Journal of Operational Research 23(3), 407-424.

[27]　Porteus, E. L. (1986). Optimal lot sizing, process quality improvement and setup cose reduction. Operations Research 34, 137-144.

[28]　Rosenblatt, M. J. and Lee, H. L. (1986). Economic production cycles with imperfect production processes. IIE Transactions 18, 2-9.
	
[29]　Roy, A., Maity, K., Kar, S. and Maiti, M. (2009). A production-inventory model with remanufacturing for defective and usable items in fuzzy-environment. Computers & Industrial Engineering 56(1), 87-96.

[30]　Su, C. H., Ouyang, L. Y., Ho, C. H. and Chang, C. H. (2007). Retailer’s inventory policy and supplier’s delivery policy under two-level trade credit strategy. Asia-Pacific Journal of Operational Research 24(5), 613-630.

[31]　Wu, K. S. and Ouyang, L. Y. (2000). Defective units in (Q, r, L) inventory model with sub-lot sampling inspection. Production Planning & Control 11(2), 179-186.

[32]　Wu, K. S. and Ouyang, L. Y. (2001). (Q, r, L) inventory model with defective items. Computers & Industrial Engineering 39, 173-185.

[33]　Wu, K. S., Ouyang, L. Y. and Ho, C. H. (2007). Integrated vendor-buyer inventory system with sublot sampling inspection policy and controllable lead time. International Journal of Systems Science 38(4), 339-350.