Method to Determine Test Profile in Step-Stress Accelerated RDT Under Type-I Censoring

Conventional Reliability Demonstration Test (RDT) based on statistical method is widely used in industry as it is simply and convenient to apply. But for the products with high reliability and long life, this test method fails to satisfy the demand for short cycle and low cost, and is liable to cause the phenomenon of over-test and short-test. This paper gives a step-stress accelerated RDT plan when the lifetime follows exponential distribution, making it faster to make decision of accept or reject. We summarize the method of stress sensitivity analysis, and use failure effect to characterize the failure mechanism by considering the non-linear phenomena between severity rating and failure effect. By raising the levels of environment stresses, the test time can be cut down remarkably. Combined with the stress profile in Reliability Qualification Test (RQT), the step-stress accelerated test profile is acquired. An example is given to illustrate the superior performance of the proposed method over traditional methods. The FIDES method based stress sensitivity analysis was studied, and the non-linear phenomena between severity rating and failure effect was considered, then the failure effect was used to characterize the failure mechanism. We proposed a step-stress accelerated reliability demonstration test plan, combining conventional statistical demonstration method with Physics of Failure (PoF), which can remarkably cut down the test time and cost. The detailed process on the establishment of accelerated test profile under multiple stresses and mechanisms was illustrated with a case example.