We discuss here the design of constant-stress accelerated life-tests for one-shot devices by assuming Weibull distribution with non-constant scale and shape parameters as a lifetime model. Since there are no explicit expressions for the maximum likelihood estimators of the model parameters and their variances, we adopt the asymptotic approach here to develop an algorithm for the determination of optimal settings of allocation of devices, inspection frequency, and the number of inspections at each stress level. The asymptotic variance of the estimate of reliability of the device at a specified mission time is minimized subject to a pre-fixed experimental budget and a termination time. Examples are provided to illustrate the proposed algorithm for the determination of the best test plan. A sensitivity analysis pf the best test plan is also carried out to examine the effect of misspecification of the model parameters. Copyright © 2014 MIT Departmental Seminar.
|Publication status||Published - Oct 2014|
Accelerated Life Test
Maximum Likelihood Estimator