Hostname: page-component-84b7d79bbc-g5fl4 Total loading time: 0 Render date: 2024-07-26T00:50:11.145Z Has data issue: false hasContentIssue false

A Study of the Role of Modules in the Failure of Systems

Published online by Cambridge University Press:  27 July 2009

Emad El Neweihi
Affiliation:
University of Illinois at Chicago, Chicago, Illinois
Jayaram Sethuraman
Affiliation:
Florida State University Tallahassee, Florida 32306

Abstract

Since the introduction of the concept of coherent systems and the description of the reliability of such systems in terms of the reliabilities of the components, the concept of importance of a component has created a new and fruitful area of research. Two distinct concepts of importance can be found in the literature. We take the view that the importance of a component or a module that is part of a system can be derived directly from the role of the component or the module in the failure of the system. Here again, it is possible that there will be several definitions of role. In this paper we define the role of a module (or component) to be the probability that the module is among all the modules (or components) that failed at the time of system failure. The role of a module depends on the structure of the system in terms of the modules, the structure of the module in terms of its components and the distribution of lifetimes of the components. In this paper we study the role of a module under several structures and distributions for lifetimes. We establish various monotonicity properties and indicate applications of these properties to optimal allocation. Another quantity that describes the nature of the components in sustaining the system is the number of components that fail at the time of the failure of the system. We establish monotonicity properties for the expected number of failed components and also indicate applications to optimal allocation.

Type
Articles
Copyright
Copyright © Cambridge University Press 1991

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barlow, R.E. & Proschan, F. (1975). Importance of system components and failure tree events. Stochastic Processes and its Applications 3: 153173.CrossRefGoogle Scholar
Boland, P.J. & El-Neweihi, E. (1990). Measures of component importance in reliability theory, University College, Dublin. Technical Report.Google Scholar
Boland, P.J., El-Neweihi, E., & Proschan, F. (1988). Active redundancy allocation in coherent systems. Probability in the Engineering and Informational Sciences 2: 343353.Google Scholar
Birnbaum, Z. W. (1969). On the importance of different components in a multicomponent system. In Krishnaiah, P.R. (Ed.), MultivariateAnalysisll. New York: Academic Press, pp. 581592.Google Scholar
El-Neweihi, E. (1980). Extensions of a simple model with applications in structural reliability, extinction of species, inventory depletion and urn sampling. Communications in Statistics. Theory and Methods A9 (4): 399414.Google Scholar
El-Neweihi, E., Proschan, F., & Sethuraman, J. (1978). A simple model with applications in structural reliability, extinction of species, inventory depletion and urn sampling. Advances in Applied Probability 10: 232254.CrossRefGoogle Scholar
Fussell, J.B. & Vesely, W.E. (1972). A new methodology for obtaining cut sets for fault trees. American Nuclear Society Transactions 15(I): 262263.Google Scholar
Marshall, A.W. & Olkin, I. (1979). Theory of Majorization and its Applications. NewYork: Academic Press.Google Scholar
Natvig, B. (1985). New light on measures of importance of system components. Scandanavian Journal of Statistics 12: 4354.Google Scholar
Pledger, G. & Proschan, F. (1971). Comparisons of order statistics and of spacings from heterogeneous distributions. In Rustagi, J. (Ed.), Optimization Methods in Statistics. New York: Academic Press, pp. 89113.Google Scholar
Ross, S.M., Shahshahani, M., & Weiss, G. (1980). On the number of component failures in systems whose component lives are exchangeable. Mathematics of Operations Research 5(3): 358365.CrossRefGoogle Scholar