Reliability analysis of degradation with a new independent increment process

Degradation test is an important method to assess the reliability of complex systems and highly reliable products. The effectiveness of a degradation model depends strongly on the suitability of the model to describe the process. This paper proposes a new degradation model in which the characteristics of the widely used stochastic process and degradation path models are considered simultaneously. According to the proposed model, closed-form expressions of the performance distribution, failure time distribution and their percentiles, as well as reliability, can be obtained easily. A one-stage procedure is then developed to estimate the model parameters, based on which, estimations of the performance distribution, failure time distribution, and reliability are also presented in the paper. Finally, simulation studies are conducted to validate the proposed method. Results suggest that the method provides precise estimates even for zero-failure cases or an extremely small sample size of approximately five.