隨科技日新月異，製造商或企業使用的機器設備日益複雜昂貴，購置設備成本與後續維修保養變得不符合經濟效益，故機器設備租賃逐漸取代傳統購置與擁有，專業設備租賃型態應運而生，並以合約約束租賃雙方權利與義務。承租者(製造商或企業)須負擔租金義務，從出租者(設備擁有者)取得設備使用權利。
一般租賃合約亦包含相關維修規定，如設備於出租期間內發生故障，出租者必須負擔維修責任；且當維修時間超過合約規定的時間時，必須額外支付懲罰性賠償予承租者做為其損失補償。因此，若出租者能於出租期間內對設備實施適當的預防保養，將有效減少出租期間內故障次數，進而降低維修及所衍生的逾時懲罰賠償成本。
本論文以設備出租者立場，在故障時採取小修方式及預防保養時採取固定失效率降低法下，考慮小修、逾時懲罰及預防保養等成本因素，建構出租者實施預防保養策略之成本模式，根據所建構模式尋求最佳預防保養策略以及發展相關演算法；並對具有韋伯壽命分配之租賃設備，提出其最佳公式解。最後，在韋伯壽命分配下與文獻上其它失效率降低法之數值結果比較，以驗證最佳預防保養策略之績效。

Due to rapid technological innovations, increased complexity of equipment, and the cost of professional technicians required maintaining equipment, it is not economical for manufacturers or businesses to own certain equipment. Therefore, there is a trend toward leasing instead of buying equipment and professional equipment leasing patterns emerged. The rights and obligations are bounded by a lease contract. The lessee (the manufacturer or business) shall have the obligation to afford the rent from the lessor (equipment owner) to obtain the right equipment for use.
The leased equipment was bundled with maintenance and offered by the lessor in the leased contract. And, the lessor may incur a penalty when repair time exceeds a specified time limit. The lessor can employ preventive maintenance (PM) actions to reduce the number of possible failures to lower the repair and penalty cost within the lease period.
This study proposes a maintenance scheme for leased equipment by using failure rate reduction method and rectifies failures with minimal repairs. Under the proposed maintenance scheme, the lessor incurs minimal repair costs, penalty costs and preventive maintenance costs. This study derives an optimal preventive maintenance (PM) policy that minimizes expected total cost in accordance with the maintenance scheme. An efficient algorithm is developed to derive the optimal PM policy and a closed-form solution is obtained for the case where the lifetime distribution of the equipment is Weibull. The proposed maintenance scheme is then compared with various failure rate reduction schemes through numerical examples to verify the performance of the optimal PM policy under the Weibull distribution.

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