Abstract
The cumulative exposure model (CEM) is often used to express the failure probability model in the step-up test method; the step-up procedure continues until breakdown occurs. This probability model is widely accepted in reliability fields because accumulation of fatigue is considered to be reasonable. Contrary to this, the independence model (IM) is also used in electrical engineers because accumulation of fatigue is not observed in some cases. We propose here a new model, the extended cumulative exposure model (ECEM), which includes both the previous models.
