Some aging classes of life distributions at specific age

This Journal is an Open Access Journal listed in the Directory of Open Access Journal (DOAJ), www.doaj.orgWe introduce some properties of the new better than used in convex ordering at age t0 (NBUC − t0) and new better than used of second order(2) at age t0 (NBU(2)−t0) classes of life distributions,where the survival probability at age 0 is greater than or equal to the conditional survival probability at specified age t0 > 0. Preservation properties of the two classes under various reliability operations and shock model are arriving according to homogeneous Poisson process are established