Inference of extended Weibull distribution using ramp stress accelerated life testing under censoring

Abstract

In this paper, the expectation-maximization (EM) algorithm and adaptive type-II progressive censoring (A-II-PC) scheme are discussed for the first time under ramp-stress accelerated life testing (RS-ALT) experiment based on extended Weibull (EW) distribution. Under the assumptions of cumulative exposure (CE) model and inverse power law relationship, the maximum likelihood estimators (MLEs) of the unknown parameters and acceleration factors are obtained using the EM algorithm, then compared with the scoring algorithm. Furthermore, the observed information matrix based on the missing value principle is computed and used to construct the asymptotic confidence intervals for the parameters and acceleration factors. Bootstrap techniques are also considered in the interval estimation. Moreover, a numerical example is presented to illustrate the application of both the scoring and EM algorithms. Finally, a Monte Carlo simulation study is carried out to assess the performance of the suggested algorithms.