Accelerated life testing (ALT) is the process of testing products by subjecting them to strict conditions in order to observe more failure data in a short time period. In this study, we compare the methods of two‐level constant‐stress ALT (CSALT) and simple step‐stress ALT (SSALT) based on competing risks of two or more failure modes with independent exponential lifetime distributions. Optimal sample size allocation during CSALT and the optimal stress change‐time in SSALT are considered based on V‐ and D‐optimality , respectively. Under Type‐I censoring, numerical results show that the optimal SSALT outperforms the optimal CSALT in a wide variety of settings. We theoretically also show that the optimal SSALT is better than the optimal CSALT under a set of conditions. A real data example is analyzed to demonstrate the performance of the optimal plans for both ALTs.

中文翻译：

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指数分布下最优加速寿命试验与竞争风险模型的比较

加速寿命测试（ALT）是指对产品进行严格测试，以在短时间内观察更多故障数据的过程。在本研究中，我们基于具有独立指数寿命分布的两种或更多种失效模式的竞争风险，比较了二级恒定应力ALT（CSALT）和简单阶梯应力ALT（SSALT）的方法。分别基于V和D最优考虑CSALT期间的最佳样本量分配和SSALT的最佳应力变化时间。在类型I审查下，数值结果表明，在各种设置中，最佳SSALT均优于最佳CSALT。从理论上讲，我们还表明，在一定条件下，最佳SSALT优于最佳CSALT。