One-Sided Confidence Intervals for the Quality Indices of a Complex Item

One-sided confidence intervals are found for the quality indices of a complex item comprising k vital components each having an exponentially distributed lifetime when life-testing data are available only for the individual components. The sampling plan consideredisthatinwhichniofcomponentiaretested untilri r i ≤ n i fail, i = 1,2, …, k. Two types of confidence intervals are obtained, one preferable for small samples or when the mean lifetimes of the components are nearly equal; the other for large samples with a wider range of mean lifetimes or in cases when there is reason to suspect the validity of the assumption of exponentially distributed lifetimes.