Allocating active redundancies to <i>k</i>‐out‐of‐<i>n</i> reliability systems with permutation monotone component lifetimes

Abstract

This paper studies k ‐out‐of‐ n redundant systems with component lifetimes having lower tail permutation decreasing probability density. For matched redundancies with stochastic arrangement increasing lifetimes, the allocation of a more reliable component to a weaker component is proved to enhance system reliability. For redundancies with independent and identically distributed lifetimes, more allocations to a weaker component are shown to stochastically increase the system lifetime. In addition, using a real data set, we illustrate the statistical aspects of developing lifetimes with lower tail permutation decreasing density. Copyright © 2016 John Wiley &amp; Sons, Ltd.