考慮不完全的預防性維護的條件下,本論文建立一個預防性維護計畫。在此計畫中,預防性維護的檢查點是在預先排定的時間表下,週期性地執行。若產品失效發生在預防性維護檢查點之間,則以最小維修來修復產品。本論文假設產品的失效模式服從非齊次卜瓦松過程,在有限的產品保固期之下,建立此一計畫的成本函數,並以最小化成本函數為條件來求得到最佳的預防性維護計畫。此外,我們藉由近似的方法來估算真正的成本與估計的成本之間的差異,並以此評估本預防性維護的品質。本文以一個實例來說明所提出的預防性維護計畫之應用。 This thesis establishes a preventive maintenance plan under an imperfect preventive maintenance policy. The preventive maintenance check points are prescheduled and implemented periodically. Moreover, the minimal repairs are done whenever the product fails between successive preventive maintenance check points. The failures of product are modeled according to a nonhomogeneous Poisson process. An expected cost function is established under a finite warranty period, and the optimal strategy is framed which minimizes the expected cost function. The asymptotically error bound between the real cost and the estimated cost is determined to assess the quality of the proposed preventive plan. Moreover, the use of the proposed method is illustrated by an example.