Inference procedures in some bivariate exponential models under hybrid random censoring

We consider a life testing experiment in whichn units are put on test, successive lifetimes (X ₁,X ₂) of both componentsC ₁ andC ₂ are recorded and the observation is terminated either at ther-th order statistic ofY _i =Min(X _1i ,X _2i ),i=1,…,n i.e.Y _(r) or a random timeT _i whichever is reached first. This mixture of random censoring and type-II censoring schemes, we call as hybrid random censoring which is of wide use. We use this censoring scheme and obtain maximum likelihood estimation of the parameters and develop large sample tests in bivariate exponential (BVE) models proposed by Marshall-Olkin (1967), Block-Basu (1974), Freund (1961) and Preschan-Sullo (1974).