在進行產品可靠度的分析及改善時，通常需要做產品的抽樣壽命實驗，希望能利 用已觀測到的產品壽命來預測尚未發生故障的樣本壽命。本計畫首先考慮所取得的樣本 型態為服從浴缸型壽命分配的右型II 設限樣本觀測值，在所取得的樣本壽命觀測值下， 利用貝氏方法預測未來產品發生故障的壽命區間; 此外，在製造業中，製程能力指標常 被用來評估產品品質是否達到所要求的水準，而壽命績效指標C L 就是評估工具之ㄧ。 其次，將以服從浴缸型壽命分配的逐步型II 設限樣本來建構壽命績效指標C L 之最大概 似估計量(MLE)，進而利用C L 之MLE 求得壽命績效指標C L 之信賴區間，同時發展一 檢定程序，以評估產品之壽命是否達到所要求的水準。最後，將以數值範例或模擬資料 說明如何應用所提出之方法，分析評估產品之壽命績效是否達到所要求的水準。 In the researching on the reliability of products and improvement, usually need to carry out life test. During life testing, the future observations in an ordered sample are often expected to be predicted. In this plan, we consider the type II censored samples from Bathtub-shaped lifetime distribution firstly. We adopt Bayesian method to obtain the prediction intervals of future ordered observation for the products under the type II censored data; Process capability analysis has been widely applied in the field of quality control to monitor the performance of industrial processes. In practice, the lifetime performance index C L is a popular means to assess the performance and potential of their processes, where L is the lower specification limit. We will also apply data transformation technology to construct a maximum likelihood estimator (MLE) of the lifetime performance index C L based on the progressively type II censored sample. The MLE of C L is then utilized to develop a new procedure of statistical inference in the condition of known L. Finally, we will give some practical examples or simulated data to illustrate the use of the procedure of statistical inference under given conditions.
