We consider a step stress life testing which is deviced for a two-component parallel system with the considerable long life time. The purpose of this paper is to suggest an optimal time for changing the stress when the simple step stress life test is ...
We consider a step stress life testing which is deviced for a two-component parallel system with the considerable long life time. The purpose of this paper is to suggest an optimal time for changing the stress when the simple step stress life test is carried out. The life distribution is assumed as the ACBVE by Block and Basu(1974) and the expanded CE model is suggested for the bivariate case.
The criterion for optimality is to minimize the variances of the maximum likelihood estimators of the mean life times under the normal stress.