The MLE of the parameter in accelerated life testing step-stress models under the exponential distribution condition based on the grouped data is presented, and the average life of the product under designed stress is obtained.

• 对指数分布场合下的寿命分布进行研究,简单步进应力加速寿命试验中,在观察时间间隔不相等的条件下,对所获得的分组数据为寿命数据,给出加速方程中未知参数的极大似然估计(MLE),从而计算出常应力下产品的平均寿命。