Mechanism Equivalence in Designing Optimum Step-Stress Accelerated Degradation Test Plan Under Wiener Process

To obtain enough reliability information of highly reliable products, step-stress accelerated degradation test becomes more and more popular as it helps to shorten test duration and reduce sample size. A reasonable step-stress accelerated degradation test plan provides a possibility to predict product's lifetime precisely when it is designed by using an appropriate optimization criterion based on the valid degradation information. In this paper, we investigate the mechanism equivalence in designing an optimum step-stress accelerated degradation test plan under Wiener process. In particular, an algorithm for extracting valid test information is formulated based on degradation mechanism equivalence analysis. Then, we propose the M-optimality criterion to improve the mechanism equivalence of a step-stress accelerated degradation test when designing an optimum plan. Subject to the total cost constraint, a comparison is carried out between the optimum plan designed by using M-optimality criterion and other plans designed by using traditional criteria through the case of light intensity degradation of LEDs.