由於資訊科技的進步及競爭市場全球化的趨勢，供應鏈存貨管理逐漸發展成一重要的領域。供應鏈存貨管理的基本精神是有效整合同一條鏈上所有的合作夥伴，使得整體供應鏈利潤最大化或是成本最小化。因此，如何決定供應鏈上合作夥伴之間的庫存策略，達到整體供應鏈最大績效，是值得探討並研究的課題。

本論文討論單一製造商與單一零售商的二階整合存貨系統，在可控制前置時間及零售商允許缺貨情況下，建立連續性檢查存貨模型，探討降低訂購成本與考慮產品品質對最適生產/訂購策略的影響。文中建構八個不同的存貨模型，共同的決策變數有訂購數量、請購點、前置時間和運送次數。首先，第一章說明研究動機與目的及相關文獻探討。第二章在生產/訂購批量中沒有不良品，零售商允許缺貨的情況下，建構可控制前置時間的整合存貨模型。第三章在前置時間的縮減與訂購數量有關，零售商允許缺貨的情況下，加入投資資金以降低訂購成本的考量，建立整合存貨模型。第四章在零售商訂購數量中含有不良品，並且允許缺貨的情況下，建立採用全部檢查策略的整合存貨模型。第五章在製造商投資資金改進不完善的生產製程，且零售商允許缺貨的情況下，建立整合存貨模型。本論文對所建構的數學模型，均建立演算法，並以數值範例說明求解程序，找出最適的訂購、生產及運送策略。同時，本論文亦分析各模型中參數值的變動對最適解所造成的影響，提供給管理者做決策之重要參考依據。最後，在第六章裡將上述各章所得的結論做一總結，並說明未來的研究方向。

Due to the improvement of information technology and the tendency of global market competition, inventory management in supply chain has become an important research issue. The basic tenet of supply chain management is to integrate business partners in a chain efficiently so as to maximize total profits or minimize total costs. Therefore, it is important to determine an efficient inventory strategy within supply chain partners to achieve the best performance of the chain. 

This thesis proposes some single-vendor single-buyer integrated inventory models with continuous review. It is assumed that shortages are allowed and lead time is controllable. Eight two-echelon inventory models are established in this thesis, and the common decision variables here are ordering quantity, reorder point, lead time and the number of lots delivered from vendor to buyer. Chapter 1 covers the motivation and objectives of this thesis. In this chapter, literature review about related research papers is also included. Chapter 2 introduces integrated inventory models with shortages in controllable lead time. Chapter 3 assumes that lead time reduction cost depends on the lead time length to be reduced and the ordering lot size. This chapter introduces integrated inventory models with controllable lead time and ordering cost reduction. Chapter 4 provides integrated inventory models for defective items in buyer’s arrival order lot with shortages and full-lot inspection policy. Chapter 5 deals with the impact of investing in quality improvement and lead time reduction on the integrated inventory models with shortages. For each integrated inventory model, this thesis established algorithm to determine the optimal strategy and numerical examples are provided to show the solution procedure. Also, sensitivity analysis is conducted for the parameters of the models. Finally, chapter 6 provides the conclusions of this thesis and some future research topics.

表目錄			V
圖目錄			VII
使用符號一覽表	VIII
基本假設	X

第一章 緒論	1
1.1	研究動機與目的	1
1.2	相關文獻探討	5
1.2.1	補貨前置時間	5
1.2.2	訂購/設置成本	7
1.2.3	產品品質	9
1.2.4	整合存貨模型	11
1.3	本文結構	15

第二章 可控制前置時間的二階整合存貨模型	18
2.1	前言	18
2.2	符號說明與假設	19
2.3	基本模型	20
2.4	前置時間內需求量之機率分配呈常態分配	25
2.5	前置時間內需求量的機率分配為未知	29
2.6	數值範例	33
2.7	小結	40

第三章 降低訂購成本與縮短前置時間的二階整合存貨模型	42
3.1	前言	42
3.2	符號說明與假設	43
3.3	降低訂購成本與縮減前置時間互相獨立的二階整合存貨  模型	46
3.4	訂購成本與前置時間具有線性關係的二階整合存貨模型  			57
3.5	數值範例	61
3.6	小結	66
第四章 批量中含有不良品的二階整合存模型 — 零售商採用全部檢查策略	68
4.1	前言	68
4.2	符號說明與假設	69
4.3	基本模型	71
4.4	前置時間內需求量之機率分配呈常態分配	78
4.5	前置時間內需求量的機率分配為未知	82
4.6	數值範例	86
4.7	小結	90

第五章 製造商投資資金以改善生產製程的二階整合存貨模型    			92
5.1	前言	92
5.2	符號說明與假設	93
5.3	基本模型	95
5.4	前置時間內需求量之機率分配呈常態分配	100
5.5	前置時間內需求量的機率分配為未知	106
5.6	數值範例	110
5.7	小結	115

第六章 結論	117
6.1	主要研究成果	117
6.2	未來研究方向	119


參考文獻	121

附錄A	135
附錄B	137
附錄C	140
附錄D	144
附錄E	146

中文文獻：
[1]大紀元。2002年1月25日，取自http://www.dajiyuan.com。
[2]自由電子新聞網。2001年3月27日，取自http://www.libertytime.com.tw。
[3]李芳齡(2004)。豐田模式。台北市：美商麥格羅.希爾國際。(譯自：The TOYOTA way /Liker, J. K.)。
[4]	唐明月(1999)。管理科學的本質。2版，台北市：松崗電腦圖書資料股份有限公司。
[5]	黃秀媛(2004)。沃爾瑪王朝。台北市：天下遠見出版股份有限公司。(譯自：The Wal-Mart Decade/Slater, R.)。
[6]	鄧東濱、林炳文(1999)。個體經濟理論。6版，台北市：三民書局。
[7]	羅偉碩(2004)。供應鏈管理。台北縣：普林斯頓國際。
[8]	蘇雄義(2003)。供應鏈之設計與管理。2版，台北市：美商麥格羅.希爾國際。(譯自：Designing and managing the supply chain: concepts, strategies, and case studies/Simchi-Levi, D., Kaminsky, P., and Simchi-Levi, E.)。

英文文獻：
[1]	Affisco, J. F., Paknejad, M. J., and Nasri, F. (2002). Quality improvement and setup reduction in the joint economic lot size model. European Journal of Operational Research, 142, 497-508.
[2]	Amasaka, K. (2002). “New JIT”: A new management technology principle at Toyota. International Journal of Production Economics, 80, 135-144.
[3]	Balkhi, Z. T. (2004). An optimal solution of a general lot size inventory model with deteriorated and imperfect products, taking into account inflation and time value of money. International Journal of Systems Science, 35(2), 87-96.
[4]	Banerjee, A. (1986). A joint economic-lot-size model for purchaser and vendor. Decision Sciences, 17, 292-311.
[5]	Banerjee, A., Pyreddy, V. R., and Kim, S. L. (1996). Investment policy for multiple product setup reduction under budgetary and capacity constraints. International Journal of Production Economics, 45, 321-327.
[6]	Ben-Daya, M. and Hariga, M. (2003). Lead-time reduction in a stochastic inventory system with learning consideration. International Journal Production Research, 41(3), 571-579.
[7]	Ben-Daya, M. and Hariga, M. (2004). Integrated single vendor single buyer model with stochastic demand and variable lead time. International Journal Production Economics, 92, 75-80.
[8]	Ben-Daya, M. and Rahim, A. (1999). Multi-stage lot sizing models with imperfect processes and inspection errors. Production Planning & Control, 10(2), 118-126.
[9]	Ben-Daya, M. and Raouf, A. (1994). Inventory models involving lead time as a decision variable. Journal of the Operational Research Society, 45(5), 579-582.
[10]	Berger, P. D., Gerstenfeld, A., and Zeng, A. Z. (2004). How many suppliers are best? A decision-analysis approach. OMEGA The International Journal of Management Science, 32, 9-15.
[11]	Billington, P. J. (1987). The classic economic production quantity model with setup cost as function of capital expenditure. Decision Sciences, 18, 25-42.
[12]	Cakanyildirim M., Bookbinder, J. H., and Gerchak, Y. (2000). Continuous review inventory models where random lead time depends on lot size and reserved capacity. International Journal of Production Economics, 68, 217-228.
[13]	Chang, H. C. (2004). An application of fuzzy sets theory to the EOQ model with imperfect quality items. Computers & Operations Research, 31, 2079-2092.
[14]	Chang, C. T. and Chang, S. C. (2001). On the inventory model with variable lead time and price – quantity discount. Journal of the Operational Rresearch Society, 52, 1151-1158.
[15]	Chen, C. K., Chang, H. C., and Ouyang, L.Y. (2001). A continuous review inventory model with ordering cost dependent on lead time. International Journal of Information and Management Sciences, 12(3), 1-13.
[16]	Chiu, P. P. (1998). Economic production quantity models involving lead time as a decision variable. Master thesis: National Taiwan University of Science and Technology.
[17]	Chu, P., Chung, K. J., and Lan, S. P. (1999). The criterion for the optimal solution of an inventory system with a negative exponential crashing cost. Engineering Optimization, 32, 267-274. 
[18]	Chuang, B. R., Ouyang, L. Y., and Chuang, K. W. (2004). A note on periodic review inventory model with controllable setup cost and lead time. Computers & Operations Research, 31, 549-561.
[19]	Coates, E. R. (1996). Manufacturing setup cost reduction. Computers & Industrial Engineering, 31(1/2), 111-114.
[20]	Das, K., Roy, T. K., and Maiti, M. (2004). Buyer-seller fuzzy inventory model for a deteriorating item with discount. International Journal of Systems Science, 35(8), 457-466.
[21]	Denizel, M., Erenguc, S., and Benson, H. P. (1997). Dynamic lot-sizing with setup cost reduction. European Journal of Operational Research, 100, 537-549.
[22]	Diaby, M. (2000). Integrated batch size and setup reduction decisions in multi-product, dynamic manufacturing environments. International Journal of Production Economics, 67, 219-233.
[23]	Gallego, G. and Moon, I. (1993). The distribution free newsboy problem: review and extensions. Journal of the Operational Research Society, 44(8), 825-834.
[24]	Goyal, S. K. (1976). An integrated inventory model for a single supplier-single customer problem. International Journal of Production Research, 15(1), 107-111.
[25]	Goyal, S. K. (1988). A joint economic-lot-size model for purchaser and vendor: a comment. Decision Sciences, 19, 236-241.
[26]	Goyal, S. K. (1995). A one-vendor multi-buyer integrated inventory model: A comment. European Journal of Operational Research, 82, 209-210.
[27]	Goyal, S. K. and Gupta, Y. P. (1989). Integrated inventory models: The buyer-vendor coordination. European Journal of Operational Research, 41, 261-269.
[28]	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.
[29]	Goyal, S. K. and Srinivasan, G. (1992). The individually responsible and rational decision approach to economic lot sizes for one vendor and many purchasers: A comment. Decision Sciences, 23, 777-784.
[30]	Ha, D. and Kim, S. L. (1997). Implementation of JIT purchasing: an integrated approach. Production Planning & Control, 8(2), 152-157.
[31]	Hadley, G. and Whitin, T. M. (1963). Analysis of Inventory Systems. New Jersey: Prentice-Hall.
[32]	Hall, R. W. (1983). Zero Inventories. Illinois: Dow Jones-Irwin, Homewood.
[33]	Hariga, M. and Ben-Daya, M. (1998). Note: The economic manufacturing lot-sizing problem with imperfect production processes: Bounds and Optimal solutions. Naval Research Logistics, 45, 423-433.
[34]	Hariga, M. and Ben-Daya, M. (1999). Some stochastic inventory models with deterministic variable lead time. European Journal of Operational Research, 113, 42-51.
[35]	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.
[36]	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.
[37]	Hong, J. D. (1997). Optimal production cycles, procurement schedules, and joint investment in an imperfect production system. European Journal of Operational Research, 100, 413-428.
[38]	Hong, J. D. and Hayya, J. C. (1995). Joint investment in quality improvement and setup reduction. Computers & Operations Research, 22(6), 567-574.
[39]	Hou, K. L. and Lin, L. C. (2004). Optimal production run length and capital investment in quality improvement with an imperfect production process. International Journal of Systems Science, 35(2), 133-137.
[40]	Huang, C. K. (2001). An integrated inventory model for supplier and retailer with defective items. Journal of Information & Optimization Sciences, 22(3), 509-519.
[41]	Huang, C. K. (2002). An integrated vendor-buyer cooperative inventory model for items with imperfect quality. Production Planning & Control, 13(4), 355-361.
[42]	Hwang, H., Kim, D. B., and Kim, Y. D. (1993). Multiproduct economic lot size models with investment costs for setup reduction and quality improvement. International Journal of Production Research, 31(3), 691-703.
[43]	Jamal, A. M. M., Sarker, B. R., and Mondal, S. (2004). Optimal manufacturing batch size with rework process at a single-stage production system. Computers & Industrial Engineering, 47, 77-89.
[44]	Joglekar, P. and Tharthare, S. (1990). The individually responsible and rational decision approach to economic lot sizes for one vendor and many purchasers. Decision Sciences, 21, 492-506.
[45]	Johnson, L. A. and Montgomery, D. C. (1975). Operations Research in Production Planning, Scheduling and Inventory Control. New York: John Wiley & Sons.
[46]	Kelle, P., Al-khateeb, F., and Miller, P. A. (2003). Partnership and negotiation support by joint optimal ordering/setup policies for JIT. International Journal of Production Economics, 81-82, 431-441.
[47]	Keller, G. and Noori, H. (1988). Impact of investing in quality improvement on the lot size model. OMEGA The International Journal of Management Science, 16(6), 595-601.
[48]	Khouja, M. (2003). The impact of quality considerations on material flow in two-stage inventory systems. International Journal of Production Research, 41(7), 1533-1547.
[49]	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.
[50]	Kim, K. L., Hayya, J. C., and Hong, J. D. (1992). Setup reduction in economic production quantity model. Decision Sciences, 23(2), 500-508.
[51]	Kim, C. H., Hong, Y., and Chang, S. Y. (2001). Optimal production run length and inspection schedules in a deteriorating production process. IIE Transactions, 33, 421-426.
[52]	Kouikoglou, V. S. and Phillis, Y. A. (2002). Design of product specifications and control policies in a single-stage production system. IIE Transactions, 34, 591-600.
[53]	Lee, H. H. (2005). A cost/benefit model for investments in inventory and preventive maintenance in an imperfect production system. Computers & Industrial Engineering, 48, 55-68.
[54]	Lee, W. (2005). A joint economic lot size model for raw material ordering, manufacturing setup, and finished goods delivering. OMEGA The International Journal of Management Science, 33, 163-174.
[55]	Lee, W. C., Wu, J. W., and Hou, W. B. (2004). A note on inventory model involving variable lead time with defective units for mixtures of distribution. International Journal of Production Economics, 89, 31-44.
[56]	Liao, C. J. and Shyu, C. H. (1991). An analytical determination of lead time with normal demand. International Journal of Operations & Production Management, 11, 72-78.
[57]	Lin, C. S., Chen, C. H., and Kroll, D. E. (2003). Integrated production-inventory models for imperfect production processes under inspection schedules. Computers & Industrial Engineering, 44, 633-650.
[58]	Lu, L. (1995). A one-vendor multi-buyer integrated inventory model. European Journal of Operational Research, 81, 312-323.
[59]	Minner, S. (2003). Multiple-supplier inventory models in supply chain management: A review. International Journal of Production Economics, 81-82, 265-279.
[60]	Montgomery, D. C., Bazaraa, M. S., and Keswani, A. K. (1973). Inventory models with a mixture of Backorders and lost sales. Naval Research Logistics Quarterly, 20(2), 255-263.
[61]	Moon, I. (1994). Multiproduct economic lot size models with investment costs for setup reduction and quality improvement: review and extensions. International Journal of Production Research, 32(12), 2795-2801.
[62]	Moon, I. and Choi, S. (1998). A note on lead time and distributional assumptions in continuous review inventory models. Computers & Operations Research, 25(11), 1007-1012.
[63]	Nasri, F., Affisco, J. F., and Paknejad, M. J. (1990). Setup cost reduction in an inventory model with finite range stochastic lead time. International Journal of Production Research, 28(1), 199-212.
[64]	Nye, T. J., Jewkes, E. M., and Dilts, D. M. (2001). Optimal investment in setup reduction in manufacturing systems with WIP inventories. European Journal of Operational Research, 135, 128-141.
[65]	Ouyang, L. Y. and Chang, H. C. (2000). Quality improvement on lot size reorder point model with partial backorders based on limited information of demand. Journal of Statistics & Management Systems, 3(1), 75-89.
[66]	Ouyang, L. Y. and Chang, H. C. (2002). Lot size reorder point inventory model with controllable lead time and set-up cost. International Journal of Systems Science, 33(8), 635-642.
[67]	Ouyang, L. Y., Chen, C. K., and Chang, H. C. (1999). Lead time and ordering cost reductions in continuous review inventory systems with partial backorders. Journal of the Operational Research Society, 50, 1272-1279.
[68]	Ouyang, L. Y., Chen, C. K., and Chang, H. C. (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.
[69]	Ouyang, L. Y. and Chuang, B. R. (2001). Mixture inventory model involving variable lead time and controllable backorder rate. Computers & Industrial Engineering, 40, 339-348.
[70]	Ouyang, L. Y., Chuang, B. R., and Wu, K. S. (1999). Optimal inventory policies involving variable lead time with defective items. Opsearch, 36(4), 374-389.
[71]	Ouyang, L. Y. and Wu, K. S. (1997). Mixture inventory model involving variable lead time with a service level constraint. Computers & Operations Research, 24(9), 875-882.
[72]	Ouyang, L. Y. and Wu, K. S. (1998). A minimax distribution free procedure for mixed inventory model with variable lead time. International Journal of Production Economics, 56-57, 511-516.
[73]	Ouyang, L. Y. and Wu, K. S. (1999). Mixture inventory model involving variable lead time and defective units. Journal of Statistics & Management Systems, 2(2-3), 143-157.
[74]	Ouyang, L. Y. and Yao, J. S. (2002). A minimax distribution free procedure for mixed inventory model involving variable lead time with fuzzy demand. Computers & Operations Research, 29, 471-487.
[75]	Ouyang, L. Y., Yeh, N. C., and Wu, K. S. (1996). Mixture inventory model with backorders and lost sales for variable lead time. Journal of the Operational Research Society, 47, 829-832.
[76]	Paknejad, M. J., Nasri, F., and Affisco, J. F. (1995). Defective units in a continuous review (s, Q) system. International Journal of Production Research, 33(10), 2767-2777.
[77]	Pan, C.-H. J. and Hsiao, Y. C. (2001). Inventory models with back-order discounts and variable lead time. International Journal Systems Science, 32(7), 925-929.
[78]	Pan, C.-H. J. and Hsiao, Y. C. (2005). Integrated inventory models with controllable lead time and backorder discount considerations. International Journal of Production Economics, 93-94, 387-397.
[79]	Pan, C.-H. J., Hsiao, Y. C., and Lee, C. J. (2002). Inventory models with fixed and variable lead time crash costs considerations. Journal of the Operational Research Society, 53, 1048-1053.
[80]	Pan, C.-H. J., Lo, M. C., and Hsiao, Y. C. (2004). Optimal reorder point inventory models with variable lead time and backorder discount considerations. European Journal of Operational Research, 158, 488-505.
[81]	Pan, C.-H. J. and Yang, J. S. (2002). A study of an integrated inventory with controllable lead time. International Journal of Production Research, 40(5), 1263-1273.
[82]	Porteus, E. L. (1985). Investing in reduced setups in the EOQ model. Management Sciences, 31(8), 998-1010.
[83]	Porteus, E. L. (1986). Optimal lot sizing, process quality improvement and setup cost reduction. Operations Research, 34(1), 137-144.
[84]	Rosenblatt, M. J. and Lee, H. L. (1986). Economic production cycles with imperfect production processes. IIE Transactions, 18(1), 48-55.
[85]	Salameh, M. K. and Jaber, M. Y. (2000). Economic production quantity model for items with imperfect quality. International Journal of Production Economics, 64, 59-64.
[86]	Sarker, B. R. and Coates, E. R. (1997). Manufacturing setup cost reduction under variable lead times and finite opportunities for investment. International Journal of Production Economics, 49, 237-247.
[87]	Sarker, B. R., Jamal, A. M. M., and Wang, S. (2000). Supply chain models for perishable products under inflation and permissible delay in payment. Computers & Operations Research, 27, 59-75.
[88]	Schwaller, R. L. (1988). EOQ under inspection costs. Production and Inventory Management Journal, 29, 22-24.
[89]	Silver E. A., Pyke, D. F., and Peterson, R. (1998). Inventory Management and Production Planning and Scheduling. 3rd ed, New York: John Wiley & Sons.
[90]	Simchi-Levi, D., Kaminsky, P., and Simchi-Levi, E. (2000). Designing and Managing the Supply Chain: Concepts, Strategies, and Case Studies. Singapore: McGraw-Hill.
[91]	Sucky, E. (2004). Coordinated order and production policies in supply chains. OR Spectrum, 26, 493-520.
[92]	Sung, C., Seo, Y., Hahm, J., and Kang, S. (2002). Coordination of investment decisions on marketing and logistics for the optimal supply chain operations. Computers & Industrial Engineering, 43, 75-95.
[93]	Tersine, R. J. (1994). Principles of Inventory and Materials Management. 4th ed, New Jersey: PTR Prentice-Hall.
[94]	Teunter, R. H. and Flapper, S. D. P. (2003). Lot-sizing for a single-stage single-product production system with rework of perishable production defectives. OR Spectrum, 25, 85-96.
[95]	Tripathy, P. K., Wee, W. M., and Majhi, P. R. (2003). An EOQ model with process reliability considerations. Journal of the Operational Research Society, 54, 549-554.
[96]	Vörös, J. (1999). Lot sizing with quality improvement and setup time reduction. European Journal of Operational Research, 113, 568-574.
[97]	Wang, C. H. and Sheu, S. H. (2001). Simultaneous determination of the optimal production-inventory and product inspection policies for a deteriorating production system. Computers & Operations Research, 28, 1093-1110.
[98]	Woo, Y. Y., Hsu, S. L., and Wu, S. (2000). Order processing cost reduction in a joint vendor-buyer inventory system via the application of information technology. The Engineering Economist, 45(4), 350-365.
[99]	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.
[100]	Wu, J. W., Lee, W. C., and Tsai, H. Y. (2003). A note on defective units in an inventory model with sub-lot sampling inspection for variable lead-time demand with the mixture of free distributions. International Transactions in Operational Research, 10, 341-359.
[101]	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.
[102]	Wu, K. S. and Ouyang, L. Y. (2001). (Q, r, L) inventory model with defective items. Computers & Industrial Engineering, 39, 173-185.
[103]	Yang, J. S. and Pan, C.-H. J. (2004). Just-in-time purchasing: an integrated inventory model involving deterministic variable lead time and quality improvement investment. International Journal of Production Research, 42(5), 853-863.
[104]	Yang, G., Ronald, R. J., and Chu, P. (2005). Inventory models with variable lead time and present value. European Journal of Operational Research, 164, 358-366.
[105]	Yang, P. C. and Wee, H. M. (2000). Economic ordering policy of deteriorated item for vendor and buyer: an integrated approach. Production Planning & Control, 11(5), 474-480.
[106]	Yang, P. C. and Wee, H. M. (2003). An integrated multi-lot-size production inventory model for deteriorating item. Computers & Operations Research, 30, 671-682.
[107]	Yao, M. J. and Chiou, C. C. (2004). On a replenishment coordination model in an integrated supply chain with one vendor and multiple buyers. European Journal of Operational Research, 159, 406-419.
[108]	Zipkin, P. H. (2000). Foundations of Inventory Management. Singapore: McGraw-Hill.