Abstract: For reasonable evaluating problems of accelerated life test(ATL), according to proposed simulation evaluation rule of accelerated life test plans, taking variance mean and standard deviation of product median life as evaluation criteria of test plan’s precision and stability, the numerical simulation and the simulation evaluation’s method of step-stress accelerated life test plans are built. Simultaneously, by using maximum likelihood estimation(MLE) theory, the mathematic model used for step-stress accelerated life test plan’s simulation evaluation is built. The result of the simulation evaluation of Y11X electrical connectors’ step-stress accelerated life test plans shows that although the more samples the better statistical accuracy and stability, compared the optimized results of electrical connectors’ step-stress ALT with the constant-stresses ALT at the same test samples, the former not only can reduce the test time, but also could keep the precision and stability of statistic as the latter, so ATL can realize fast evaluation of electromechanical products with high reliability and long life.

Key words: Accelerated life test, Simulation evaluation, Step-stress