製程能力指標近年來被製造商廣泛運用在品質監控上,藉由指標值來評估製程能力的好壞。對於產品壽命之相關分配,在實務上可利用壽命績效指標CL來衡量產品的壽命績效,其中L為規格下界。而在壽命試驗中常因時間的限制以及人力和成本的考量而無法取得完整樣本資料,因此在本文將採用設限樣本資料。 本文的主要目的是利用雙二設限樣本來評估Burr XII和極值之雙參數壽命分配之產品的壽命績效指標CL,並利用CL的不偏估計量,建立相關的檢定程序與信賴區間,再針對壽命績效指標的檢定力及信賴區間進行蒙地卡羅模擬。經由模擬結果顯示,不論樣本個數n、設限樣本個數r、s如何變動,檢定力與信賴區間的模擬平均值均非常接近真實值。最後,透過實例分析,說明各項程序的運用,以提供給製造商評估產品的壽命是否符合所要求的水準。
In recent years, many process capability indices (PCIs) have been widely used in qality monitoring by many manufacturing industries.In practice, the lifetime performance index CL is utilized to measure lifetime performance for products with some lifetime distributions, where L is the lower specification limit. In lifetime testing experiments, we may not be able to obtain a complete sample due to time limitation or other restrictions. Therefore, censored samples arise in practice. This research constructs an unbiased estimator of CL based on the doubly type II censored sample from Burr XII and Extreme value distribution,respectively.The unbiased estimator of CL is then utilized to develop a hypothesis testing procedure and the confidence interval in the condition of known L. The purchasers can then employ the new hypothesis and the confidence interval to determine whether the lifetime performance of products adhere to the required level.