Common-cause Failures Research Articles

An availability calculation for k-out-of- N redundant system with common-cause failures and replacement

This paper presents a k-out-of- N:G three-state unit redundant system availability model including common-caue failures. The steady-state probability and system availability equations are developed. Further, the frequency of encountering a state and the average duration of residence in a state are also derived.

Markovian Reliability Analysis Under Uncertainty with an Application on the Shutdown System of the Clinch River Breeder Reactor

A methodology for the assessment of uncertainties about reliability of nuclear reactor systems described by Markov models is developed, and the uncertainties about the failure probability of the shutdown system of the Clinch River Breeder Reactor (CRBR) are assessed. Failure and repair rates and all other inputs of reliability analysis are taken as random variables with known probability distribution functions (pdf's). The pdf of reliability is calculated by both a Monte Carlo simulation and a Taylor series expansion approximation. Three techniques are developed to reduce the computational effort: (a) ordering of system states, (b) merging of Markov processes, and (c) judicious choice of time steps. A Markov model has been used for reliability analysis under uncertainty of the shut down system of the CRBR. It accounts for common-cause failures, interdependences between unavailability of the system and occurrence of transients, and inspection and maintenance procedures that depend on the state of the system and that include possibility of human errors. Under these conditions, the failure probability of the shutdown system differs significantly from that computed without common-cause failures, human errors, and input uncertainties.

Multi-state device redundant systems with common-cause failures and one standby unit

This paper presents two mathematical models. Model I represents a two identical unit active redundant system whose units may fail in either of the two mutually exclusive failure modes. Similarly, model II represents a two non-identical unit active parallel system whose units either fail or survive. In addition, models I and II comprise the occurrence of common-cause failures and one standby unit. Systems are only repaired when all the system units fail (including the standby unit). System repair times are arbitrarily distributed. Laplace transforms of the state probability equations are developed.

Common-cause failure analysis of a three-state device system : Balbir S. Dhillon, A. Sambhi and M. R. Khan. Microelectron. Reliab.19, 345 (1979)

Common-cause failure analysis of a three-state device system : Balbir S. Dhillon, A. Sambhi and M. R. Khan. Microelectron. Reliab.19, 345 (1979)

A 4-Unit Redundant System with Common-Cause Failures

This note presents a mathematical model to represent a system containing 2-failure-mode devices with common-cause failures. Laplace transforms of the state probability equations are developed.

A 1-out-of-N:G System with Duplex Elements

This paper presents a mathematical model containing s-identical duplex systems, N-1 of which are standbys. The one operational duplex system is subject to common-cause failures. Laplace transforms of the state probability equations are developed.

Common-cause failure analysis of a three-state device system

This paper presents an extension to the classical theory to incorporate common-cause failures when analyzing a parallel redundant network composed of three-state devices. Formulas for the redundant system reliability, mean-time-to-failure (MTTF) and system hazard rate are developed by assuming constant common-cause and other failure rates. Plots for network reliability, mean-time-to-failure and system hazard rate are presented.

A n-unit redundant system with common-cause failures

A mathematical model representing a N-unit redundant system containing two failure modes units with common-cause failures has been developed. Laplace transforms of state probabilities are derived.

Common-Cause Outages In Multiple Circuit Transmission Lines

Reliability evaluation of a power system involving both generation and transmission elements is extremely complex. Outages of these elements are usually considered to be s-independent events. Recent investigations, however, have indicated that common-cause outages of multicircuit transmission configurations can appreciably affect the predicted reliability. Closed form expressions for steady state probabilities in 2- and 3-line cases (including certain common-cause failures) are developed. These expressions provide transmission-line state probabilities for composite generation and transmission system reliability studies. The procedure can also be used to develop state probabilities for other line models and for systems with four or more lines on the same right-of-way. The examples show the influence of the common-cause outage rate on the state probabilities. There is a definite need to include commoncause outages in reliability evaluation of transmission systems. This will require a more comprehensive approach to collecting transmission line outage data than has previously been used by most utilities.

A k-out-of- n three-state devices system with common-cause failures

A device is said to have three-states if it operates normally in its operational mode but fails in either opened or shorted (closed) modes. This paper presents a repairable k-out-of- n three-state device network model with common-cause failures. Laplace transforms of the state probability equations are developed.

A 4-unit redundant system with common-cause failures : Balbir S. Dhillon. IEEE Trans. Reliab.R-26, (5) 373 (December 1977)

A 4-unit redundant system with common-cause failures : Balbir S. Dhillon. IEEE Trans. Reliab.R-26, (5) 373 (December 1977)

On common-cause failures—Bibliography

This paper presents a brief introduction and extensive list of selective bibliography on common-cause failures

A 4-Unit Redundant System with Common-Cause Failures

This theoretical note presents a mathematical model of a 4-unit (i.i.d.) redundant system subject to common-cause failures (s-dependent failures). Laplace transforms of the state probability equations are developed.

Common-Cause Failure Considerations in Predicting HTGR Cooling System Reliability

Probabilistic safety analyses of the High Temperature Gas Cooled Reactor are being performed by the General Atomic Company. The project is sponsored by the Energy Research and Development Administration and is known as Accident Initiation and Progression Analysis. Probabilistic methods are used to estimate the probability of failure of the HTGR cooling systems.

Common-cause failure considerations in predicting HTGR cooling system reliability : Karl N. Fleming and G. William Hannaman. IEEE Trans. Reliab.R-25 (3), 171 (August 1976)

Common-cause failure considerations in predicting HTGR cooling system reliability : Karl N. Fleming and G. William Hannaman. IEEE Trans. Reliab.R-25 (3), 171 (August 1976)

Reliability analysis of the system

This paper presents a k-out-of N:G redundant system with M cold standby units, r repair facilities and common-cause failures. The constant failure rates of the operating and cold standby units are different. Failed system repair times are arbitrarily distributed. The system is in a failed state when (N+M−k+1) units failed or a common-cause occurred. Laplace transforms of the state probabilities, the availability of the system and the system steady-state availability are derived.