Assessing device reliability based on scheduled discrete degradation measurements

Degradation measurements are increasingly important in reliability studies because few failures are observed during the short time of many experiments. In this article, we assess device reliability from discrete degradation processes under scheduled inspections. In some particular situations, since the degradation quantities of the device characteristic are only observed specifically at the scheduled time points, the exact occurrence time and the corresponding damage amount of each degradation event are not recorded. For this sort of situation, there are plenty of examples such as the amount of shock damages of the database in a computer system, the amount of fatigues of the shock absorber for a car, and the amount of growth of a metal crack on an aircraft.