Optimal Design of Failure Step Stress Partially Accelerated Life Tests with Type II Censored Inverted Weibull Data

This article provides the optimum simple failure step stress partially accelerated life tests (FSS-PALTs) and statistical inferences for the model parameters and acceleration factor in which items are run at both accelerated and use conditions. It is assumed that the lifetime of the test items follows inverse Weibull distribution under type II censoring. The maximum likelihood estimators (MLEs), asymptomatic variance-covariance matrix, and the confidence bounds of the model parameters and acceleration factor are obtained via MathCAD"14". The optimum test a plan specifies the optimal stress switching point is determined by minimizes the generalized asymptotic variance of the MLEs for the model parameters. Finally, the numerical studies are applied to illustrate the proposed procedures.