For a consecutive-k-out-of-n system of components with independent and identically distributed increasing failure rate (IFR) lifetimes, Cui et al. (Probab. Engng. Inform. Sci. 9 (1995) 217) proved that for any fixed k, there exists an nk for which the system does not preserve IFR when nnk. On...

The (n,f,k) (<n,f,k>) system consists of n components ordered in a line or a circle and the system fails if and only if there exist at least f failed components or (and) at least k consecutive failed components. This type of models involves two common failure criteria of a system. In this paper, the...</n,f,k>

The (n,f,k) system consists of n components ordered in a line or a cycle, while the system fails if, and only if, there exist at least f failed components or at least k consecutive failed components. For the linear (n,f,k) system with equal component reliabilities, the system reliability formula...