現今環境變化快速，在及時生產系統風潮下，廠商大多期望使用最少的原物料、在製品及完成品之庫存，以降低成本。而且市場漸漸以買方為主，除了要求賣方產品品質、產品即時交付、提升顧客滿意度等等，賣方還得考量到自身的生產成本，而這些問題皆成為每個企業所面臨到困境。在預防保養的概念普及下，爲防止系統產生失效、減緩元件老化的速度或使設備回復至較新的狀態，延長元件壽命，透過經濟方面的考量，來衡量在最適當的時間執行預防保養活動。當生產系統出現非預期的失效或預期的維修活動，而影響系統供應速率時，針對系統停頓所產生之需求，提供一定量存貨，以應付系統停頓期間。本研究便是針對兩製程的可修復系統的經濟製造批量模式(EMQ)，讓製造商在生產規劃階段時，衡量生產批次間整備的相關問題，而隨著預防保養活動的影響會，製造商的生產規劃便會延伸許多不一樣的情境。因此在上游生產系統預防保養期間，下游裝配系統依其生產條件的考量下，本研究估計預期元件失效的維修成本。由維修成本、存貨持有成本及缺貨成本考量，透過單位時間期望成本最小化，透過雙方拉扯的過程中，來建構預防保養週期時間與緩衝存貨的決策問題。使決策者有效制定最適緩衝存貨數量。最後再透過實證應用分析發現存貨持有成本影響本研究建構之模式最深，且下游生產率與重置時間也具有相當影響力。
最後透過討論本研究模式深入探討生產系統的最適緩衝存貨數量與預防保養週期的結果，讓未來更可以根據可修復退化的系統或是多機台多製程的考量，以提供管理者在進行預防保養規劃時，能更接近現實狀況的考量。

In the JIT philosophy, the manufacturer should seriousing determine the production lot to reduce costs in uncertain environment by considering the quality of the products, on time delivery, and customer satisfaction improvement etc. These aspects all become the essential issues that each enterprise has to face. Preventive maintenance actions need to be undertaken for the failure mitigation. During each interruption, a buffer is needed so that normal operations will not be interrupted. The optimal buffer level is determined by trading off the holding cost and the shortage cost. A system with two subsystem is considered where the production subsystem and buffers are included in order to provide to the assemble subsystem which has a set-up procedure. This study uses the economic manufacturing quantity (EMQ) model to determine the proper production lot size by minimizing the cost components which involve the production cost, the inventory holding cost, and the shortage cost if the stockout happenes. The model can assist the decision maker to determine the optimal buffer size and the preventive maintenance cycle. The numerical application suggests that the holding cost is
the most important factor which influence the optimal policy.

一、中文部分

陳耀茂，民89，「機率過程導論」，五南，臺北市

二、英文部分
Abdul-Kader, W. (2006), “Capacity improvement of an unreliable production line – n analytical approach”, Computers & Operations Research, vol.33, pp.1695-1712.

Ascher, H. & Freingold, H. (1984), Repairable Systems Reliability, Marcel Dekker, New York.

Ben-Daya, M. (2002), “The economic production lot-sizing problem with imperfect production processes and imperfect maintenance”, International Journal of Production Economics, vol.76, pp.257-264.

Carnero, M.C. (2006), “An evaluation system of the setting up of predictive maintenance programmes”, Reliability Engineering and System Safety, vol.91, pp.945-963.

Celeux, G., Corset, F., Lannoy, A. & Ricard, B. (2006), “Designing a Bayesian network for preventive maintenance form expert opinions in a rapid and reliable way”, Reliability Engineering and System Safety, vol.91, pp.849-856.

Chen, D. & Trivedi, K.S. (2005), “Optimization for condition-based maintenance with semi-Markov decision process”, Reliability Engineering and System Safety, vol.90, pp.25-29.

Chen, D. & Trivedi, K.S. (2002), “Closed-form analytical results for condition-based maintenance”, Reliability Engineering and System Safety, vol.76, pp.43-51.

Cheung, K.L. & Hausman, W.H. (1997), “Joint determination of preventive maintenance and safety stocks in an unreliable production environment”, Naval Research Logistics, vol.44, pp.257-272.

Clarotti, C., Lannoy, A., Odin, S. & Procaccia, H. (2004), “Detection of equipment aging and determination of the efficiency of a corrective measure”, Reliability Engineering and System Safety, vol.84, pp.57-64.

Coetzee, J.L. (1997), “The role of NHPP models in the practical analysis of maintenance failure data”, Reliability Engineering and System Safety, vol.56, pp.161-168.

Cooke, R.M. (2005), Bosma, A. & Harte, F., “A practical model of Heineken’s bottle filling line with dependent failures”, European Journal of Operational Research, vol.164, pp.491-504.

Cox, D.R. & Lewis, P.A.W. (1966), “The Statistical Analysis of Series of Events”, Chapman and Hall, London.

Dohi, T., Okamura, H. & Osaki, S. (2001), “Optimal control of preventive maintenance schedule and safety stocks in an unreliable manufacturing environment”, International Journal of Production Economics, vol. 74, pp.147-155.

Doyen, L. & Gaudoin, O. (2004), “Classes of imperfect repair models based on reduction of failure intensity or virtual age”, Reliability Engineering and System Safety, vol.84, pp.45-56.

Fariaa, J., Matos, M. & Nunes, E. (2006), “Optimal design of work-in-process buffers”, International Journal of Production Economics, vol. 99, pp.144-155.

Giri, B.C., Yun, W.Y. & Dohi, T. (2005), “Optimal design of unreliable production-inventory systems with variable production rate”, European Journal of Operational Research, vol.162, pp.372-386.

Hamada, M., Martz, H.F., Berg, E.C. & Koehler, A.J. (article in press, 2005), “Optimizing he product-based availability of a buffered industrial process”, Reliability Engineering and System Safety.

Hsieh, C.C. & Chiu, K.C. (2002), “Optimal maintenance policy in a multistate deteriorating standby system”, European Journal of Operational Research, vol.141, pp.689-698.
Huang, Y.S. (2001), “A decision model for deteriorating repairable systems”, IIE Transactions, vol.33, pp.479-485.

Kamath, R.K. & Pakkala, T.P.M. (2002), “A Bayesian approach to a dynamic inventory model under an unknown demand distribution”, Computers & Operations Research, vol.29, pp.403-422.

Kuo, Y. (2006), “Optimal adaptive control policy for joint machine maintenance and product quality control”, European Journal of Operational Research, vol.171, pp.586-597.

Lee, H.H. (2005), “A cost/benefit model for investments in inventory and preventive maintenance in an imperfect production system”, Computers & Industrial Engineering, vol. 48, pp.55-68.

Leung, K.N.F., (article in press, 2005), ”A generalized geometric-programming solution to‘‘An economic production quantity model with flexibilityand reliability considerations’’”, European Journal of Operational Research,

Lin, D., Zuo, M.J. & Yam, R.C.M. (2001), “Sequential imperfect preventive maintenance models with two categories of failure modes”, Naval Research Logistics, vol.48, pp.172-183.

Levitin, G. & Meizin, L. (2001), “Structure optimization for continuous production systems with buffers under reliability constraints”, International Journal of Production Economics, vol. 70, pp.77-87.

Lofsten H. (2000), “Measuring maintenance performance- in search for a maintenance productivity index”, International Journal of Production Economics, vol.63, pp.47-58.

Martorell, S., Sa´nchez, A., Carlos, S. & Serradell, V. (2002), “Comparing effectiveness and efficiency in technical specifications and maintenance optimization”, Computers & Operations Research , vol.77, pp.281-289.

Mohebbi, E., (2004) “A replenishment modelfor the supply-uncertainty problem,” Internatonal Journal of Production Economics, vol.87, pp.25-37

Montoro-Cazorla, D. & Pe´rez-Oco´n, R. (2006), “A deteriorating two-system with two repair modes and sojourn times phase-type distributed”, Reliability Engineering and System Safety, vol.91, pp.1-9.

Nahas, N., Ait-Kadi, D. & Nourelfath M. (article in press, 2006), “A new approach for buffer allocation in unreliable production lines”, International Journal of Production Economics,

Panagiotidou, S. & Tagaras, G. (article in press, 2006), “Optimal preventive maintenance for equipment with two quality states and general failure time distributions”, European Journal of Operational Research.

Patchong, A. & Willaeys, D. (2001), “Modeling and analysis of an unreliable flow line composed of parallel-machine stages”, IIE Transactions, vol.33, pp.559-568.

Percy, D.F. & Kobbacy, K.A.H. (2000), “Determining economical maintenance intervals”, International Journal of Production Economics, vol.67, pp.87-94.

Perry, D. & Posner, M.J.M. (2002), “A mountain process with state dependent input and output and a correlated dam”, Operations Research Letters, vol.30, pp.245-251.

Pham, H. (2003), “Software reliability and cost models: Perspectives, comparison, and practice”, European Journal of Operational Research, vol.149, pp.475–489.

Ribeiro, M.A., Silveira, J.L. & Qassim, R.Y. (article in press, 2005), “Joint optimisation of maintenance and buffer size in a manufacturing system”, European Journal of Operational Research.

Rigdon, S.E. & Basu, A.P. (2000), Statistical methods for the reliability of repairable systems, Wiley, New York.

Robinson, E. P. & Sahin, F. (2001), “Economic production lot sizing with periodic cost and overtime, “ Decision Sciences, vol.32, pp.423-452

Rosvist, T. (2002), “Stopping time optimization in condition monitoring”, Reliability Engineering and System Safety, vol.76, pp.319-325.

Salameh, M.K. & Ghattas, R.E. (2001), “Optimal just-in-time buffer inventory for regular preventive maintenance”, International Journal of Production Economics, vol. 74, pp.157-161.

Sheu, S.H., Lin,Y.B. & Liao, G.L. (2006), “Optimum policies for a system with general imperfect maintenance”, Reliability Engineering and System Safety, vol.91, pp.362-369.

Sheu, S.H., Yeh, R.H., Lin, Y.B. & Juang, M.G. (1999), “A Bayesian perspective on age replacement with minimal repair”, Reliability Engineering and System Safety, vol.65, pp.55-64.

Sheu, D.D. & Lin, J. (2006), “Equipment management strategy under machine capacity loss”, International Journal of Production Economics, vol.103, pp.308-315.

Sorensen, K. & Janssens, G.K. (2001), “Buffer allocation and required availability in a transfer line with unreliable machines”, International Journal of Production Economics, vol. 74, pp.163-173.

Tempelmeier, H. & Burger, M. (2001), “Performance evaluation of unbalanced flow lines with general distributed processing times, failures and imperfect production”, IIE Transactions, vol.33, pp.293-302.

Tsai, Y.T., Wang, K.S. & Tsai, L.C. (2004) “A study of availability-centered preventive maintenance for multi-component systems”, Reliability Engineering and System Safety, vol.84, pp.261-270.

Valdez-Flores, C. & Feldman, R.M. (1989), “A survey of preventive maintenance models for stochastically deteriorating single-unit systems”, Naval Research Logistics, vol. 36, pp.419–446.

Vaughan, T.S. (2005), “Failure replacement and preventive maintenance spare parts ordering policy”, European Journal of Operational Research, vol.161, pp.183-190.

Wang, H. (2002), “A survey of maintenance policies of deteriorating systems”, European Journal of Operational Research, vol.139, pp.469-489.

Zhao, Y.X. (2003), “On preventive maintenance policy of a critical reliability level for system subject to degradation”, Reliability Engineering and System Safety, vol.79, pp.301-308.