Multi‐sample simple step‐stress experiment under time constraints

In the context of accelerated life testing, a step‐stress model allows for testing under different conditions at various intermediate stages of the experiment. The goal is to develop inference for the mean lifetime at each stress level. The maximum likelihood estimates (MLEs) exist only when some (at least one) failures are observed at each stress level. This limitation can be tackled by a multi‐sample step‐stress model, which imposes a weaker …