A zero-failure reliability demonstration approach based on degradation data

Conventional zero-failure reliability demonstration test is widely used in industry as it is simply and convenient to apply. This test method concentrates on whether there are failure products in a certain test time. But for the products with high reliability and long life, this test method is ineffective to satisfy the constraints on the limited development time and test cost, because it requires excessive test time or a large sample size. Some high reliability and long life products in their failure process have an obvious feature of degradation. By the use of this feature, the reliability of the products can be validated in a short cumulative test time through the design of reliability demonstration approach. In this paper, an approach of zero-failure reliability demonstration based on the accelerated degradation data for Weibull distribution is presented. The accelerated degradation data obtained during the test is used to BS degradation model and an acceleration equation. Based on the failure threshold of degradation, the failure probability of the products is calculated in a certain test time, and simultaneously combined with Type Π error, decision rules for terminating the test of a unit is presented. Then, we develop the optimum test plans, which choose the minimum sample, and the excepted test time, by minimizing the test time, and satisfying the constraints on the Type Π error, available sample size and the total test cost.