隨著科技日新月異，保證契約成為行銷產品設備的策略之一，買賣雙方並以保證契約約束著彼此的權利與義務。一般保證契約亦包含相關維修規定，如產品設備於保證期內發生故障，賣方(製造商)必須負擔維修責任；相對地，若非保證期內故障，買方(消費者)須自行負擔維修費用。本論文以買方(消費者) 購入機台設備立場，探討可維修機台在一有限區間下，當機台設備在免費小修保證期內生產運轉時，賣方須負擔保證期內機台失效之故障費用，而買方需自行負擔因機台設備故障後所引發的當機成本。本文以買方觀點，分別建立了三種機台設備保證長度與機台置換時間之期望總利潤模式，並推導出三種模式下，使期望總利潤最高之最佳置換時間。最後，以數值範例分析說明執行保證契約的機台設備在有限區間下對期望總利潤的影響。

With the advancement of technology, surety bond to become one of the strategies for marketing products equipment buyers and sellers to ensure that the contract bound by mutual rights and obligations. General to ensure that the contract also contains maintenance requirements, such as product equipment to ensure the failure period, the seller (manufacturer) have to bear the maintenance responsibility;, unless the warranty period failure, the buyer (consumer) must pay for maintenance costs. The papers to the buyer (consumer) purchase of equipment, machine position to explore a serviceable machine in a finite interval, when the machine equipment in the free minor repairs to ensure production operations during the period, the seller have to bear to ensure the failure of the fault period machine costs, the buyer will be borne by the cost of crashes caused due to equipment, machine failure. The buyer point of view, the establishment of the three machine equipment to ensure the length and machine replacement time of the expected total profit mode, and deduced three modes, so expect the highest total profits of the optimal replacement time. Finally, a numerical example analysis shows that the implementation of the guarantee contract machine equipment in the finite interval, the expected total profit.

[1]楊宗豫，「保證策略風險分析─不可維修產品的比較研究」，國立台灣工業技術學院管理技術研究所工業管理學程碩士論文，1995。
[2]陳彥年，「估計可維修產品保證成本之延伸模式」，國立台灣工業技術學院管理技術研究所工業管理學程碩士論文，1996。
[3]葉瑞徽，「產品保證對最佳維修策略之影響」，國科會研究計畫NSC-91-2213-E-011-091, 2002.
[4]林貞儀，「免費小修對產品年齡置換策略的影響」，國立台灣科技大學工業管理系碩士論文，2004。
[5]高國欽，「失效率降低法下租賃設備之最佳預防保養策略」，國立台灣科技大學工業管理系博士論文，2009。
[6]張展綸，「有限區間下具免費小修保固之可維修產品最佳單次置換時間」，國立台灣科技大學工業管理系碩士論文，2011。
[7]Barlow, R. E. and Hunter, L. C., “Optimum preventive maintenance policies,” Operations Research, 8, 90-100 (1960).
[8]Blischke, W. R., “Mathematical models for analysis of warranty policies,” Mathematical Computational Modeling,13, 1-16 (1990).
[9]Boland, P. J., “Periodic replacement when minimal repair costs vary with time,” Navel Research Logistics Quarterly, 29, 541-546 (1982).
[10]Chukova, S. and Johnston, M. R., “Two-dimensional warranty repair strategy based on minimal and complete repairs,” Mathematical and Computer Modelling, 44, 1133-1143 (2006).
[11]Jack, N. and Schoutern, F. V. D., “Optimal repair-replace strategies for a warranty,” Journal of Production Economics, 67, 95-100 (2000).
[12]Karmarker, U. S., “Future costs of service contracts for consumer durable goods,” AIIE Transactions, 10, 380-387 (1978).
[13]Monga, A. and Zuo, M. J., “Optimal system design considering maintenance and warranty,” Computers and Operations Research, 25, 691-705 (1998).
[14]Murthy, D. N. P. and Djamaludin, I., “New product warranty: A literature review,” International Journal of Production Economics, 79, 231-260 (2002).
[15]Muth, E. J., “An optimal decision rule for repair vs replacement,” IEEE Transactions on Reliability, 26, 179-181 (1977).
[16]Nakagawa, T., “A summary of periodic replacement with minimal repair at failure,” Journal of the Operational Research Society of Japan, 24(3), 231-227 (1981).
[17]Nakagawa, T. and Kowada, M., “Analysis of a system with minimal repair and its application to replacement policy,” European Journal of Operational Research, 12, 176-182 (1983).
[18]Nguyen, D. G. and Murthy, D. N. P., “A general model for estimating warranty costs for repairable products,” IIE Transactions, 16, 379-386 (1984).
[19]Nguyen, D. G. and Murthy, D. N. P., “Optimal reliability allocation for products sold under warranty,” Engineering Optimization,13,35-45 (1988).
[20]Polatoglu, H. and Sahin, I., “Probability distribution of cost, revenue and profit over a warranty cycle,” European Journal of Operational Research, 108, 170-183 (1998).
[21]Sheu, S. H., “Periodic replacement when minimal repair costs depend on the age and the number of minimal repair for a multi-unit system,” Microelectron Reliability, 30-4, 713-718 (1990).
[22]Sheu, S. H., Griffith, W. S. and Nakagawa, T., “Expected optimal replacement model with random minimal repair costs,” European Journal of Operational Research, 85, 636-649 (1995).
[23]Tadikamalla, P. R., “Age replacement policies for weibull failure time,” IEEE Transactions on Reliability, 29-1, 88-90 (1980).
[24]Tilquin, C. and Cleroux, R., “Block replacement polices with general cost structures,” Technometrics, 17-3, 291-238 (1975a).
[25]Tilquin, C. and Cleroux, R., “Periodic replacement with minimal repair at failure and general cost function,” Journal of Statistical Computing and Simulation, 4(1), 63-67 (1975b).