Using Degradation Data to Assess Reliability

For highly reliable products, little information about reliability is provided by lifetests using a practical test duration in which few or no failures are typically observed. In this article, we illustrate the advantages of using degradation data to assess reliability. We use a Bayesian approach for analyzing the degradation data because of its advantages. The uncertainty of reliability and lifetime distribution quantile estimates can be determined in a straightforward manner. Moreover, calculating for a specified time the reliability of a population of units with varying ages is easily done. We illustrate these advantages by a laser degradation example.