BAYESIAN DESIGN FOR ACCELERATED LIFE TESTING

In this paper we study experimental design for accelerated life tests where the lifetimes have either lognormal distributions or Weibull distributions. We assume that the quantities of interest are quantiles of the lifetime distribution at a specified stress and that the log lifetime decreases as a function of stress. There is an upper limit on the stress that can be used in the experiment and a fixed period of time in which to perform the experiment so that there is type I censoring when the experiment is terminated. Examples are given and it is shown that locally optimal designs, which correspond to putting a point mass prior distribution on the parameters, are very similar to Bayesian designs, which allow for prior uncertainty in the parameter values.