Читать книгу System Reliability Theory - Marvin Rausand - Страница 41

Throughout this book, it is assumed that the time‐to‐failure and the repair time of an item are random variables with probability distributions that describe the future behavior of the item. The future behavior may be evaluated based on one or more reliability metrics. A reliability metric is a “quantity” that is derived from the reliability model and is, as such, not directly measurable. When performance data become available, we may estimate or predict quantitative values for each reliability metric.

A single reliability metric is not able to tell the whole truth. Sometimes, we need to use several reliability metrics to get a sufficiently clear picture of how reliable an item is.