Estimation in Constant-Stress Accelerated Life Testing for Birnbaum-Saunders Distribution under Censoring

Accelerated life testing is a method for estimating the reliability of products at normal use conditions from the failure data obtained at the severe conditions. In this paper, constant-stress accelerated life testing is considered when the lifetime of a product follows a two- parameter Birnbaum-Saunders distribution. Based on type-II censoring. A certain conditions (stress) are assumed to affect the scale parameter through the inverse power law model. Maximum likelihood estimators (MLEs) of an accelerated life tests model are derived. Prediction of the scale parameter under usual conditions is obtained. Moreover, the reliability function at a certain mission time under the same conditions is also predicted. Simulation results are carried out to study the precision of the MLEs for the parameters involved.