Component Redundancy Versus System Redundancy in Different Stochastic Orderings

Abstract

Stochastic orders are useful to compare the lifetimes of two systems. We discuss both active redundancy as well as standby redundancy. We show that redundancy at the component level is superior to that at the system level with respect to different stochastic orders, for different types of systems.Index Terms-Coherent system, -out-of-system, reliability, stochastic orders. ACRONYMSAND ABBREVIATIONS st usual stochastic sp stochastic precedence hr hazard rate rhr reversed hazard rate lr likelihood ratio up shifted hazard rate down shifted hazard rate up shifted reversed hazard rate up shifted likelihood ratio down shifted likelihood ratio NOTATION underlying nonnegative random variable probability density function of random variable cumulative distribution function of random variable survival (reliability) function of random variable hazard rate function of random variable reversed hazard rate function of random variable lifetime of a coherent system Manuscript

On relative ageing of coherent systems with dependent identically distributed components

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