製程能力分析被發展用以品質績效的評估。在實務上，壽命績效指標(^是用以評 估品質績效的受歡迎方法，其中L是規格下限。大多數製程能力指標都假設商品的品質 特性是常態分配。然而很多商品的壽命模式是非常態分配，包括指數分配、柏拉圖分 配、韋伯分配等等。並且在壽命測試實驗中，設限資料是經常發生的。爲了使用壽命績 效指標CV能更實際與準確地評估商品的壽命績效。本研究提出一個分析非常態品質資 料的新方法。在商品的壽命模式是韋伯分配而且是右型II設限樣本的假設之下，利用冪 次資料轉換技巧去建立一個Q的最大概似估計式。然後此最大概似估計式用以發展一 個新的假設檢定程序。而此新的假設檢定程序是一個品質績效評估系統，管理者利用這 新的假設檢定程序去確定商品的品質績效是否達到規格要求，並且加強製程能力。

Process capability analysis has been developed for assessing quality performance. In practice, lifetime performance index CL is a popular means to assess quality performance, where L is the lower specification limit. Most capability indices assume that the quality characteristic has a normal distribution. Nevertheless, the lifetime model of many products generally may possess a non-normal distribution which including exponential, Pareto or Weibull distribution and so forth. Moreover, censored samples may arise in life testing experiments. In this study, a new approach of analyzing non-normal quality data is proposed. Applying the power data transformation technology, this study constructs a maximum likelihood estimator (MLE) of CL under the Weibull distribution with the right type II censored sample. The MLE of CL is then utilized to develop the new hypothesis testing procedure in the condition of known L. The new hypothesis testing procedure is a quality performance assessment system. Moreover, the managers can then employ the new testing procedure to determine whether the quality performance of products adheres to the required level.