Optimal Allocation of Active Spares in Series Systems and Comparison of Component and System Redundancies
Optimal Allocation of Active Spares in Series Systems and Comparison of Component and System Redundancies
复制标题
DOI：
10.1239/jap/1238592114
复制
发表时间：
2009-03
影响因子：
1
通讯作者：
N. Misra;I. D. Dhariyal;Nitin Gupta
中科院分区：
文献类型：
--
作者：
N. Misra;I. D. Dhariyal;Nitin Gupta
我们考虑的问题，分配k个活动备件的n个组件的串联系统，以优化其寿命。在n个部件的寿命服从分布函数F（x）同分布，k个备件的寿命服从分布函数G（x）同分布，部件和备件的寿命独立分布，ln（G（x））/ln（F（x））在x方向上递增的假设下，证明了备件均衡分配策略使系统的失效率函数最优.此外，在假设n个部件的寿命是随机序的，k个备件的寿命是同分布的，以及部件和备件的寿命是独立分布的条件下，我们证明了备件均衡分配策略上级将更多的部件分配给更强的部件的策略.对于由n个相同的冗余（备用）部件的n个相同的组件组成的相干系统，我们比较了组件和系统的冗余策略下的标准颠倒的故障率和似然比排序。当备件和原始部件的寿命分布不一定匹配时，在相干系统的结构上，给出了部件冗余策略上级系统冗余策略的一个充分条件.结果表明，对于n中取r系统，在失效率逆序准则下，元件冗余策略比系统冗余策略具有上级优势。当备件和原部件的寿命分布匹配时，在系统结构上给出了部件冗余策略上级系统冗余策略的一个充要条件.因此，我们表明，对于r-out-of-n系统，备件和原始部件的寿命分布匹配，组件冗余的策略是上级系统冗余的策略下的似然比排序。
We consider the problem of allocating k active spares to n components of a series system in order to optimize its lifetime. Under the hypotheses that lifetimes of n components are identically distributed with distribution function F(⋅), lifetimes of k spares are identically distributed with distribution function G(⋅), lifetimes of components and spares are independently distributed, and that ln(G(x))/ln(F(x)) is increasing in x, we show that the strategy of balanced allocation of spares optimizes the failure rate function of the system. Furthermore, under the hypotheses that lifetimes of n components are stochastically ordered, lifetimes of k spares are identically distributed, and that lifetimes of components and spares are independently distributed, we show that the strategy of balanced allocation of spares is superior to the strategy of allocating a larger number of components to stronger components. For coherent systems consisting of n identical components with n identical redundant (spare) components, we compare strategies of component and system redundancies under the criteria of reversed failure rate and likelihood ratio orderings. When spares and original components do not necessarily match in their life distributions, we provide a sufficient condition, on the structure of the coherent system, for the strategy of component redundancy to be superior to the strategy of system redundancy under reversed failure rate ordering. As a consequence, we show that, for r-out-of-n systems, the strategy of component redundancy is superior to the strategy of system redundancy under the criterion of reversed failure rate ordering. When spares and original components match in their life distributions, we provide a necessary and sufficient condition, on the structure of the coherent system, for the strategy of component redundancy to be superior to the strategy of system redundancy under the likelihood ratio ordering. As a consequence, we show that, for r-out-of-n systems, with spares and original components matching in their life distributions, the strategy of component redundancy is superior to the strategy of system redundancy under the likelihood ratio ordering.