Stochastic analysis of two non-identical unit parallel system incorporating waiting time

Abstract

Purpose

The purpose of this paper is to evaluate various reliability metrics such as transition state probabilities, availability, reliability, mean time to failure and expected profit of two non-identical unit parallel system incorporating waiting time.

Design/methodology/approach

The present paper investigates the reliability of two non-identical unit parallel system with two types of failures: common cause failure and partial failure. Moreover, waiting time to repair, a significant aspect of reliability analysis, has also been incorporated. The considered system is assumed to function properly if at least one of the units is in operative mode. The present system is examined by using the supplementary variable technique and Laplace transformation.

Findings

Numerical calculation shows that the availability and the reliability of the system is minimum when the system is without partial failure and is maximum when the system is free from common cause failure. Finally, the cost analysis of the system reveals that the expected profit decreases with increase in service cost.

Originality/value

This paper presents a mathematical model of two dissimilar unit parallel system, through which the performance of the considered system can be improved.

Citation

Chopra, G. and Ram, M. (2017), "Stochastic analysis of two non-identical unit parallel system incorporating waiting time", International Journal of Quality & Reliability Management, Vol. 34 No. 6, pp. 817-832. https://doi.org/10.1108/IJQRM-06-2016-0075