Designs and comparison of simple stress accelerated life tests for Weibull-half-logistic distribution based on progressive Type I censoring and a cost constraint

Abstract

The goal of this paper is to design and compare the simple constant and step stress accelerated life tests (CSALTs and SSALTs) for the Weibull-half-logistic failure data based on progressive Type I censoring and a cost constraint. Due to resource limitations in practice,an accelerated life test is effectively implemented when the stress duration is accurately determined at the design stage. The cost of testing and the accuracy of parameter estimation are affected by the duration of stress. Based on the five optimal criteria, the optimal stress duration is compared when the total testing costs do not exceed a pre-determined budget. Through the numerical results, it can be seen that the test cost and time can be reduced with the cost limit. It is concluded that in both types of stress and unconstrained test mode, the least cost and time is for the C-optimal design. Finally and for illustrative purposes, a real data set has been studied and analyzed.