Comparing limiting availabilities of a k-out-of-n : G system and a k-component series system with $$(n-k)$$ spare components

Abstract

The limiting availability of an ordinary k-out-of-n : G system can be improved simply by operating exactly k operable units while keeping any other operable units on cold standby. We establish this truth when there are different numbers of repair facilities, the repair time is exponential, and either each component has an exponential lifetime, or each component is made up of m identical sub-components that operate sequentially, with each sub-component having an exponential lifetime.