Kateri, Maria; Kamps, Udo; Balakrishnan, Narayanaswamy - In: Computational Statistics & Data Analysis 55 (2011) 1, pp. 236-247
In simple step-stress experiments under Type-II censoring with the cumulative exposure model and exponentially distributed lifetimes, maximum likelihood estimates (MLE) of the expected lifetimes may not exist due to the absence of failure times either before or after the stress change point. For...