Title: Estimating system reliability with correlated component failures

Authors: Lance Fiondella, Swapna S. Gokhale

Addresses: Department of Computer Science & Engineering, University of Connecticut, Storrs, CT 06269, USA. ' Department of Computer Science & Engineering, University of Connecticut, Storrs, CT 06269, USA

Abstract: Correlated component failures, recognised to be a major impediment in the power of redundancy to improve system reliability, need to be factored into the reliability assessment of fault-tolerant systems. In this paper, we present a methodology to derive an approximate analytical expression for mean reliability of on-demand systems with correlated failures. Applying the methodology, we derive expressions for the mean reliability of common redundant structures, namely, k-out-of-n, series-parallel and bridge systems. We illustrate the potential of these expressions to systematically assess the influence of pairwise component correlations on system reliability. An examination of the error between the system reliability estimates obtained from the analytical expressions to those obtained from simulations indicates that our method accurately captures the trends in system reliability and can hence provide a computationally faster alternative to simulation for system reliability analysis.

Keywords: structured systems; common-mode failures; system reliability; reliability estimation; component failures; fault-tolerant systems; fault tolerance.

DOI: 10.1504/IJRS.2010.032445

International Journal of Reliability and Safety, 2010 Vol.4 No.2/3, pp.188 - 205

Published online: 02 Apr 2010 *

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