Multicomponent joint reliability importance of series-in-parallel and parallel-in-series systems
International Journal of Quality & Reliability Management
ISSN: 0265-671X
Article publication date: 29 July 2014
Abstract
Purpose
Joint reliability importance (JRI) of components is the effect of a change of their reliability on the system reliability. The authors consider two coherent multi-component systems – a series-in-parallel (series subsystems arranged in parallel) and a parallel-in-series (parallel subsystems arranged in series) system. It is assumed that all the components in the subsystems are independent but not identically distributed. The subsystems do not have any component in common. The paper aims to discuss these issues.
Design/methodology/approach
For both the systems, the expressions for the JRI of two or more components are derived. The results are extended to include subsystems where some of the components are replicated.
Findings
The findings are illustrated by considering bridge structure as a series-in-parallel system wherein some of the components are repeated in different subsystems. Numerical results have also been provided for a series-in-parallel system with unreplicated components. JRI for various combinations of components for both the illustrations are given through tables or figures.
Originality/value
Chang and Jan (2006) and Gao et al. (2007) found the JRI of two components of series-in-parallel system when the components are identical and independently distributed. The authors derive the JRI of m=2 components for series-in-parallel and parallel-in-series systems when components are independent but need not be identically distributed. Expressions are obtained for the above-mentioned systems with replicated and unreplicated components in different subsystems. These results will be useful in analyzing the joint effect of reliability of several components on the system reliability. This will be of value to design engineers for designing systems that function more effectively and for a longer duration.
Keywords
Acknowledgements
The third author is grateful to Dr Satish Kumar, Director T.B.R.L, Pravendra Kumar, Group Director, J. Santhosarajan, Sc ‘E’ (Divisional Head, Technologies Development Division) for their support to pursue this work.
Citation
Jain, K., Dewan, I. and Rani, M. (2014), "Multicomponent joint reliability importance of series-in-parallel and parallel-in-series systems", International Journal of Quality & Reliability Management, Vol. 31 No. 7, pp. 858-876. https://doi.org/10.1108/IJQRM-06-2011-0087
Publisher
:Emerald Group Publishing Limited
Copyright © 2014, Emerald Group Publishing Limited