The Step-stress Life-testing with Random Stress-change Times under Exponential Distribution
指数分布下具有随机应力转换时间的截尾步加寿命试验

The step-stress life-testing with random stress-change times under exponential distribution is studied, when the samples are censored. We set up the model of test when the stress change times are order statistics from the lifetime distribution under the lower stress level. Moreover, an optimum test plan is explored by minimizing the asymptotic variance of the maximum likelihood estimates of the mean life at a design stress. At last, an example illustrates the feasibility and efficiency of the optimum test plan.