Optimal allocations of stress levels and test units in accelerated life tests

Accelerated life testing (ALI) is a widely used approach that estimates reliability of components or systems at normal operating conditions using data obtained at accelerated conditions. The accuracy of reliability estimates depends on the stress types, stress levels and corresponding sample sizes. In this paper, we present an efficient and practical approach for determining the appropriate stress levels and sample sizes of test units so as to obtain the most accurate reliability estimates at normal operating conditions. This approach relaxes the assumption. about the failure time distribution.