全球化時代，市場競爭愈趨激烈，企業要創造利潤並提高附加價值，就需要讓供應鏈體系中的物流、資訊流和金流管理能夠完全整合。信用交易亦稱為「信貸」或「賒購」，是為企業最普遍使用和接受的短期資金來源。供應商經常藉由提供信用交易來提升銷售量，降低存貨；同時，零售商亦可以利用在賒帳期間銷售貨品所得到的收入投資獲利。過去許多研究都證實付款方式會影響零售商的訂購以及庫存。隨著商業環境的改變和信用交易使用的頻繁，至今，已有不少文獻探討有關信用交易的存貨模式。但因信用交易的形式日新月異，許多目前已廣被使用的信用交易條件不是被忽略就是未納入研究考量。
    本論文以供應鏈的觀點，運用管理科學的計量方法，透過數學模式的建立，探討在供應商和零售商存貨整合的情況下，三個廣被使用的信用交易條件對供應鏈整體獲利的影響。本論文包含五個章節，第一章首先說明本論文之研究動機與目的、相關文獻探討和論文結構。第二章研究在供應商和零售商同時提供信用交易的情況下，當產品的需求情形會隨零售商所提供賒帳期間的長短變動時，決定使得供應鏈整體獲利最大的最適訂購、運送以及存貨策略。第三章則探討當零售商於特定期間內提早付清貨款就可享受價格折扣的優惠；否則，就必須在最後付款限期內付清全額貨款的情況下，買賣雙方應如何共同定訂最適的零售價格、訂購週期、訂購數量，以及在一個生產週期中供應商運送給零售商的次數，而使得供應鏈整體獲利有最大值。第四章討論當供應商提供的信用交易條件與零售商訂購的數量有關時，買賣雙方應如何共同定訂最適決策，使得供應鏈整體獲利有最大值。最後，第五章對本文各章所建構的存貨模式做一總結，同時提出未來的研究方向。

Under the progression in globalization and fierce market competitions, in order to create benefits and raise additional value, the coordination of three basic flows within the supply chain, material/product flow, information flow, and cash/ finances flow, is necessary to enterprises. Trade credit, also called “buy on credit”, is the most general short-term capital source used by enterprises. The supplier often offers a trade credit to improve sales and reduce stocks on hand. Also, retailer can utilize the selling income during credit period to profit. Many reports have verified that the payment methods offered by the supplier will influence the ordering decision and inventory control. Though many inventory models related to trade credit have been reported so far, with the change of business environment and progression of trade credit policies, many already widely used trade credit terms either been neglected or not considered.
    In light of the lack of research dealing with the operational impact of trade credit policies, in this thesis we propose three integrated inventory models under the trade credit conditions. Chapter 1 involves the motivation and objective of this thesis. In this chapter, literature review about relative research papers is also included. Chapter 2 presents a stylized model to determine the optimal strategy for the integrated supplier-retailer inventory model under the condition that both the supplier and retailer have adopted a trade credit strategy. The market demand for the item increases exponentially with the customer’s credit period. By analyzing the total channel profit function, we develop an algorithm to simultaneously determine the retailer’s optimal order quantity and the number of shipments per production run from the supplier to the retailer. In chapter 3, we develop an integrated supplier-buyer inventory model with the assumption that the market demand is sensitive to the retail price and the supplier adopts a trade credit policy. The trade credit policy discussed in this chapter is a “two-part” strategy: cash discount and delayed payment. That is, the supplier offers the buyer a cash discount if payment is made before a specified period, and if the buyer does not pay within the specified period, the full purchasing price must be paid before the delay payment due date. The objective of this chapter is to determine the optimal pricing, ordering, shipping, and payment policy to maximize the joint expected total profit per unit time. In Chapter 4, the effect of an order-size dependent trade credit on the total integrated profit is taken into account. An integrated inventory control model, making joint economic lot sizes of the buyer’s ordering and the supplier’s production batch, are developed to maximize the total expected profit per unit time. Finally, concluding remarks are made in Chapter 5, and future research directions are proposed.

目次

目錄	II
表目錄	IV
圖目錄	V
使用符號一覽表	VI
基本假設	VII
 


目錄

第1章 緒論	1
1.1 研究動機與目的	1
1.2 相關文獻探討	4
1.2.1	信用交易	4
1.2.2	整合存貨模式	7
1.2.3	生產與需求型態	10
1.3 本文架構	12
第2章 供應商與零售商皆提供信用交易之整合供應鏈存貨模式	14
2.1 前言	14
2.2符號說明與假設	16
2.3模式的建立	16
2.3.1	供應商的單位時間總利潤	17
2.3.2	零售商的單位時間總利潤	19
2.3.3	供應鏈的單位時間總利潤	22
2.4求解步驟	24
2.5 數值範例	28
2.6小結	31
第3章 供應商為促使顧客提前付款提供價格折扣之整合供應鏈存貨模式	32
3.1 前言	32
3.2符號說明與假設	34
3.3模式的建立	35
3.3.1	供應商的單位時間總利潤	35
3.3.2	零售商的單位時間總利潤	36
3.3.3	供應鏈的單位時間總利潤	39
3.4求解步驟	40
3.5 數值範例	47
3.6小結	55
第4章 信用交易的賒帳期間與訂購數量有關之整合供應鏈存貨模式	56
4.1 前言	56
4.2符號說明與假設	57
4.3模式的建立	58
4.3.1	供應商的單位時間總利潤	59
4.3.2	零售商的單位時間總利潤	59
4.3.3	供應鏈的單位時間總利潤	61
4.4求解步驟	62
4.5 數值範例	73
4.6	小結	77
第5章 結論	78
5.1	主要研究成果	78
5.2	未來研究方向	80
參考文獻	82
附錄A. 證明若Ｇ1≦０，則Π2(ｎ,Ｔ)是Ｔ的一個凹函數	88
附錄B 供應商和零售商獨立決策時的最適解	89
 


表目錄

表號	
表1.1	整合存貨模式	9
表2.1	本章所建立的供應鏈模式與相關研究的比較	15
表2.2	在不同的θ值下最適解彙整表	28
表2.3	在不同的Ｍ和Ｎ值下最適解彙整表	30
表3.1	本章所建立的供應鏈模式與相關研究的比較	34
表3.2 	不同的信用交易條件下供應鏈的獲利情形	50
表3.3	供應鏈系統的最適解	51
表3.4	不同條件下供應鏈系統的獲利比較	53
表3.5	敏感度分析	54
表4.1	本章所建立的供應鏈模式與相關研究的比較	57
表4.2	範例4.1的信用交易條件	73
表4.3	範例4.1的計算結果	73
表4.4	範例4.2的信用交易條件	75
表4.5	範例4.2的計算結果	75
表4.6	獨立決策vs.共同決策的獲利情形	76



圖目錄

圖號
圖1.1	二選一的信用交易政策示意圖	6
圖2.1	供應商的存貨模式	17
圖2.2	零售商存貨模式的利息賺得和機會成本	21
圖2.3	當供應商提供不同的賒帳期間Ｍ時，零售商的獲利情形。	31
圖3.1-1	當Ｔ＜Ｍj 時，零售商存貨模式的利息收入	37
圖3.1-2	當Ｔ≧Ｍj時，零售商存貨模式的機會成本	38
圖3.1-3	當Ｔ≧Ｍj時，零售商存貨模式的利息收入	38
圖3.2	對於固定的ｎ值(例如ｎ=8,12,50 )供應鏈單位時間的總利潤	48
圖3.3	對於ｎ=1,2,…100供應鏈單位時間的總利潤	49
圖 4.1	信用交易的賒帳期間與訂購數量有關時，供應鏈系統的總利潤函數圖形 (ｎ=15,ｐ=6.5 )	66
圖 4.2	最適解的求解程序	72
圖 4.3	存貨系統電腦分析系統	74

[1]	Abad, P.L., 2003. Optimal price and lot size when the supplier offers a temporary price reduction over an interval. Computers and Operations Research 30, 63-74.
[2]	Aggarwal, S.P. and Jaggi, C.K., 1995. Ordering policies of deteriorating items under permissible delay in payments. Journal of the Operational Research Society 46, 658-662.
[3]	Arcelus, F.J. and Srinivasan G., 1987. Inventory policies under various optimizing criteria and variable markup rate. Management Science 33, 756-762.
[4]	Arcelus, F.J. and Srinivasan G., 1993. Integrating working capital decisions. The Engineering Economist 39, 1-15.
[5]	Arcelus, F.J. and Srinivasan G., 1998. Ordering policies under one time only discount and price sensitive demand. IIE Transactions 30, 1057-1064.
[6]	Arcelus, F.J., Shah, N.H. and Srinivasan, G.., 2001. Retailer’s response to special sales: price discount vs. trade credit. OMEGA 29, 417-428.
[7]	Banerjee, A., 1986. A joint economic-lot-size model for purchaser and vendor. Decision Sciences 17, 292-311.
[8]	Bhunia, A.K. and Maiti, M., 1997. Deterministic inventory models for variable production. Journal of the Operational Research Society 48, 221-224.
[9]	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 EPQ. Computers and Operations Research 30, 1509-1524.
[10]	Brigham, E.F., 1995. Fundamentals of financial management, The Dryden Press, Florida.
[11]	Burkart, M. and Ellingsen, T., 2004. In-Kind Finance: A theory of trade credit. American Economic Review 94, 569-590.
[12]	Chang, C.T., 2002. Extended economic order quantity model under cash discount and payment delay. International Journal of Information and Management Sciences 13(3), .57-69, 
[13]	Chang, C.T., 2004. An EOQ model with deteriorating items under inflation when supplier credits linked to order quantity. International Journal of Production Economics 88, 307-316.
[14]	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 Modelling 27, 983-996.
[15]	Cheng, T.C.E., 1991. An economic order quantity model with demand-dependent unit production cost and imperfect production processes. IIE Transactions 23, 23–28.
[16]	Chopra, S., Lovejoy, W. and Yano, C., 2004. Five decades of operations management and the prospects ahead. Management Science 50(1), 8-14.
[17]	Chung, K.J., 1997. Bounds for production lot sizing with machine breakdown. Computers and Industrial Engineering 32(1), 139–144.
[18]	Chung, K.J., Goyal, S.K. and Huang, Y.F., 2005. The optimal inventory policies under permissible delay in payments depending on the ordering quantity. International Journal of Production Economics 95, 203-213.
[19]	Chung, K.J. and Liao, J.J., 2004. Lot-sizing decisions under trade credit depending on the ordering quantity. Computers and Operations Research 31, 909-928.
[20]	Chung, K.J. and Liao, J.J., 2006. The optimal ordering policy in a DCF analysis for deteriorating items when trade credit depends on the order quantity. International Journal of Production Economics 100, 116-130.
[21]	Curry, J. and Kenney, M., 1999. Beating the clock: corporate responses to rapid change in the pc industry. California Management Review 42(1), 8-36.
[22]	Fisman, R. and Love, I., 2003. Trade credit, financial intermediary development and industry growth. The Journal of Finance 58(1), 353-374.
[23]	Gallego, G., 1993. Reduced production rates in the economic lot scheduling problem. International Journal of Production Research 31(5), 1035–1046.
[24]	Gallego, G. and Moon, I., 1992. The effect of externalizing setups in the economic lot scheduling problem. Operations Research 40, 614–619.
[25]	Goswami, A. and Chaudhuri, K.S., 1992. Variations of order level inventory models for deteriorating items. International Journal of Production Economics 27, 111–117.
[26]	Goyal, S.K., 1976. An integrated inventory model for a single supplier-single customer problem. International Journal of Production Research 15, 107-111.
[27]	Goyal, S.K., 1985. Economic order quantity under conditions of permissible delay in payment. Journal of the Operational Research Society 36, 335-338.
[28]	Goyal, S.K., 1988. A joint economic-lot-size model for purchaser and vendor: a comment. Decision Sciences 19, 236-241.
[29]	Goyal, S.K., 1995. A one-vendor multi-buyer integrated inventory model: a comment. European Journal of Operational Research 82, 209-210.
[30]	Goyal, S.K., 2000. On improving the single-vendor single-buyer integrated production inventory model with a generalized policy. European Journal of Operational Research 125, 429–430.
[31]	Goyal, S.K. and Nebebe, F., 2000. Determination of economic production-shipment policy for a single-vendor-single-buyer system. European Journal of Operational Research 121, 175–178.
[32]	Ha, D. and Kim, S.L., 1997. Implementation of JITpurchasing: an integrated approach. Production Planning and Control, 8(2), 152-157.
[33]	Harris, F.W., 1913. How many parts to make at once. Factory. The Magazine of Management 10, 135-136.
[34]	Hahm, J. and Yano, C.A., 1992. The economic lot and delivery scheduling problem: the single item case. International Journal of Production Economics 28, 235–251.
[35]	Hall, R., 1992. Price changes and order quantities: impacts of discount rate and storage costs. IIE Transactions 24, 104-10.
[36]	Hayek, P. A. and Salameh, M. K., 2001. Production lot sizing with the reworking of imperfect quality items produced. Production Planning and Control 12(6), 584–590.
[37]	Hill, N.C. and Riener, K.D., 1979. Determining the cash discount in the firm’s credit policy. Financial Management 8, 68-73.
[38]	Hill, R.M., 1997. The single-vendor single-buyer integrated production-inventory model with a generalized policy. European Journal of Operational Research 97, 493-499.
[39]	Hill, R.M., 1999. The optimal production and shipment policy for the single-vendor single-buyer integrated production-inventory problem. International Journal of Production Research 37(11), 2463-2475.
[40]	Hofmann, E., 2005. Supply Chain Finance: some conceptual insights. In: Lasch, R./ Janker, C.G. (Hrsg.): Logistik Management - Innovative Logistikkonzepte, Wiesbaden, 203-214.
[41]	Hong J.D., Cavalier T.M. and Hayya, J.C., 1993. On the (t, Sj) policy in an integrated production inventory model with time proportional demand. European Journal of Operational Research 69, 154–165.
[42]	Hoque, M.A., and Goyal, S.K., 2000. An optimal policy for a single-vendor single-buyer integrated production-inventory system with capacity constraint of the transport equipment. International Journal of Production Economics, 65, 305-315.
[43]	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.
[44]	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.
[45]	Huang, Y.F., 2004. An EOQ model under trade credit linked to order quantity using algebraic method. Journal of Applied Sciences 4 (3), 432-438.
[46]	Jamal, A.M., B.R. Saker and S. Wang, 1997. An order policy for deteriorating items with allowable shortage and permissible delay in payments. Journal of the Operational Research Society 48, 826-833.
[47]	Jeffrey, H., 2002. Trade credit and the bank lending channel. Journal of Money, Credit and Banking 34(1), 226-253.
[48]	Joglekar, P.N., 1988. Comments on a quantity discount pricing model to increase vendor profits. Management Science 34, 1391-1398.
[49]	Kalir, A. and Arzi, Y., 1998. Optimal design of flexible production lines with unreliable machines and infinite buffers. IIE Transactions 30, 391-399.
[50]	Kelle, P., Al-khateeb, F. and Anders Miller, P., 2003. Partnership and negotiation support by joint optimal ordering/setup policies for JIT. International Journal of Production Economics 81-82, 431-441.
[51]	Khan, L.R. and Sarker, R.A., 2002. An optimal batch size for a JIT manufacturing system. Computers and industrial engineering 42, 127–136.
[52]	Khouja, M. and Mehrez, A., 1996. Optimal inventory policy under different supplier credit policies. Journal of Manufacturing Systems 15, 334-339.
[53]	Kim, J.S., Hwang, H. and Shinn, S.W., 1995. An optimal credit policy to increase wholesaler’s profit with price dependent demand function. Production Planning and Control 6, 45-50.
[54]	Kim, S.L. and Ha, D., 2003. A JIT lot-splitting model for supply chain management: Enhancing buyer–supplier linkage. International Journal of Production Economics 86, 1–10.
[55]	Kim, Y.H. and Chung, K.H., 1990. An integrated evaluation of investment in inventory and credit: a cash flow approach. Journal of Business Finance and Accounting 17, 381-390.
[56]	Kingsman, B.G., 1983. The effect of payment rules on ordering and stock holding in purchasing. Journal of the Operational Research Society 34(11), 1085-1098.
[57]	Kunreuther, H. and Richard, J., 1971. Optimal pricing and inventory decisions for nonseasonal items. Econometrica 39, 173-175.
[58]	Lee, H.L. and Rosenblatt, M., 1987. Simultaneous determination of production cycle and inspection schedules in a production system. Management Science 33, 1125–1136.
[59]	Lieber, Z. and Orgler, Y.E., 1975. An integrated model for accounts receivable management. Management Science 22( 2), 212-219.
[60]	Lin, G.C. and Gong, D.C., 2006. On a production-inventory system of deteriorating items subject to random machine breakdowns with a fixed repair time.  Mathematical and Computer Modelling 43, 920-932.
[61]	Lu, L., 1995. A one-vendor multi-buyer integrated inventory model. European Journal of Operational Research 81, 312-323.
[62]	Martin, G., 1994. Note on an EOQ model with a temporary sale price. International Journal of Production Economics 37, 241-243.
[63]	Monahan J.P., 1984. A Quantity Discount Pricing Model to Increase Vendor Profits Management Science 30(6), 720-726.
[64]	Ng, C.K., Kiholm Smith, J. and Smith, R.L., 1999. Evidence on the determinants of verified terms used in interfirm trade. Journal of Finance 54, 1109-1130.
[65]	Nielsen, J.H., 2002. Trade credit and the bank lending channel. Journal of Money, Credit, and Banking 34, 226–253.
[66]	Ouyang, L.Y., Chen M.S. and Chuang, K.W., 2002. Economic order quantity model under cash discount and payment delay. International Journal of Informational and Management Science 13, 1-10. 
[67]	Ouyang, L.Y., Ho, C.H. and Su, C.H., 2005. Optimal strategy for the integrated vendor-buyer inventory model with adjustable production rate and trade credit. International Journal of Informational and Management Science 16, 19-37.
[68]	Ouyang, L.Y., Teng J.T., Chuang K.W. and Chuang B.R., 2005. Optimal inventory policy with noninstantaneous receipt under trade credit. International. Journal of Production Economics 98; 290-300.
[69]	Pan, J.C.H., and Yang, J.S., 2002. A study of an integrated inventory with controllable lead time. International Journal of Production Research 40(5), 2002.
[70]	Petersen, M.A. and Rajan, R.G., 1995. The effect of credit market competition on lending relationships. The Quarterly Journal of Economics 110, 407–443.
[71]	Petersen, M.A. and Rajan, R.G., 1997. Trade credit: theory and evidence. Review of Financial Studies 10, 661–691.
[72]	Porter, M., 1985. Competitive advantage: creating and sustaining superior performance. New York: The Free Press.
[73]	Rahim, M. A. and Ben-Daya, M., 2001. Joint determination of production quantity, inspection schedule, and quality control for an imperfect process with deteriorating products. Journal of the Operational Research Society 52, 1370–1378.
[74]	Salameh, M.K., Abboud, N.E., El-Kassar, A.N. and Ghattas, R.E., 2003. Continuous review inventory model with delay in payments. International Journal of Production Economics 85, 91-95.
[75]	Schweitzer, P.J. and Seidmann, A., 1991. Optimizing processing rates for flexible manufacturing systems. Management Science 37, 454-466.
[76]	Shah, V.R., Patel, N.C. and Shah, D.K., 1988. Economic ordering quantity when delay in payments of order and shortages are permitted. Gujarat Statistical Review 15(2), 52-56.
[77]	Shinn, S.W. and Hwang, H., 2003. Optimal pricing and ordering policies for retailers under order-size-dependent delay in payments. Computers and Operations Research 30, 35-50. 
[78]	Silver, E.A., 1990. Deliberately slowing down output in a family production context. International Journal of Production Research 28(11), 17-27.
[79]	Teng, J.T., 2002. On the economic order quantity under conditions of permissible delay in payments. Journal of the Operational Research Society 53, 915-918.
[80]	Teng, J.T., Chang, C.T. and Goyal, S.K., 2005. Optimal pricing and ordering policy under permissible delay in payments. International Journal of Production Economics 97, 121-129.
[81]	Teng, J.T., Ouyang, L.Y. and Chen, L.H., 2006. Optimal manufacturer’s pricing and lot-sizing policies under trade credit financing. International Transactions in Operational Research 13, 1-14.
[82]	Tersine, R. and Price, R., 1981. Temporary price discounts and EOQ. Journal of Purchasing and Materials Management 17, 23-27.
[83]	Urban, T.L., 1992. An inventory model with an inventory level-dependent demand rate and relaxed terminal conditions. Journal of the Operational Research Society 43, 721–724.
[84]	Viswanathan, S., 1998. Optimal strategy for the integrated vendor-buyer inventory model. European Journal of Operational Research 105, 38-42.
[85]	Whitin, T., 1955. Inventory control and price theory. Management Science 2, 61-68.
[86]	Wilson, N. and Summers, B., 2002. Trade credit terms offered by small firms: survey evidence and empirical analysis. Journal of Business Finance and Accounting 29, 317-351.
[87]	Woo, Y.Y., Hsu, S.L. and Wu, S., 2001. An integrated inventory model for a single vendor and multiple buyers with ordering cost reduction. International Journal of Production Economics 73, 203-215.
[88]	Zhou, Y.W., 1995. A production-inventory model for a finite time-horizon with linear trend in demand and shortages. Systems Engineering 5, 43-49.
[89]	Zhou, Y.W., 1996. Optimal production policy for an item with shortages and increasing time varying demand. Journal of the Operational Research Society 47, 1175-1183.
[90]	唐明月，1999，管理科學的本質，台北市：松崗書局。
[91]	周成超、胡志，2002，醫院藥品存貨管理存在問題思考，中國醫院管理 22（2）： 27 – 28。
[92]	和河魚，2005，淺談如何加強存貨管理，山西冶金 100(4)：49 – 50。