Lifetime of Multistate k-out-of-n Systems

A multistate k‐out‐of‐n system model is an extension of binary k‐out‐of‐n system model by allowing multiple performance levels for the system and its components. Various definitions of multistate k‐out‐of‐n system model have been proposed in the literature. Previous studies on these systems mostly focus on reliability evaluation algorithms. The present paper investigates the lifetimes of multistate systems. In particular, the lifetimes of two different multistate k‐out‐of‐n system models are represented in terms of order statistics, and bounds and approximations are presented using these representations. The results are illustrated for a multistate system whose components' degradation occurs according to a Markov process.