Step And Order And The Statistical Analysis Of The Composite Test

In Reliability Statistics,ALT is paid close attention,especially step-stress ALT.T But there's usually a defect in discussion of accelerated life testing-step-stress model, that is the chang from lower stress environment to higher environment is instantaneous. But it's unreasonable, becouse it's hard to achieve in testing, e.g. temperature.In order to remedy this defect, in the paper, a new testing model is given: testing compounded of step-stress and progressive-stress. Idiscuss analysis of data in circle ALT under Exponential Distribution, Weibull Distribution and Log-Normal Distribution, give MLE of uncertain parameter, both for complete sample and censored sample. In the paper, a simulated data under Exponential Distribution is given.