Active Redundancy Allocation Strategy at Component and System Level

TL;DR

This paper investigates optimal strategies for allocating non-matching active redundancies in coherent systems with dependent components to enhance reliability, providing theoretical conditions and examples.

Contribution

It introduces new sufficient conditions for optimal redundancy allocation in systems with dependent components modeled via copulas, applicable to various distributions.

Findings

Derived conditions for optimal redundancy placement at component and system levels.

Guarantees likelihood ratio and reversed hazard orderings between systems.

Established aging properties related to redundancy allocation strategies.

Abstract

Researchers and practitioners in the field of reliability engineering and optimization frequently use active redundancy techniques to intensify the performance of systems. In this article, we study allocation strategies of non-matching active redundancies (spares) in coherent systems consisting of possibly dependent and identical components for achieving better system reliability. The dependence of the components is modeled through copulas using the distortion function. Sufficient conditions are derived to establish optimal allocation strategies for two heterogeneous active redundancies at the component or system levels. Moreover, the results are true for the component lifetimes following a general family of parametric distributions. The results guarantee the likelihood ratio (reversed hazard) ordering between the coherent systems at the component level (system level) active redundancies. Some aging properties are also established in this endeavor. Several examples are provided to demonstrate the theoretical results.