Performance assessment of a multi-state computer network system in series configuration using copula repair
Praveen Kumar Poonia
Abstract
The analysis of various reliability measures of a computer network system comprising two load balancers (LB), five web servers (WB), and three database replica servers (DBRS) as a series parallel system with four subsystems working under k-out-of-n methodology is described in this paper. Failure rates of LB/WB/DBRS in all the subsystems are constant and follow exponential distribution, whereas the repair follows two kinds of distributions namely general and copula distribution. Using transition diagram, first-order partial differential equations are developed and solved using supplementary variable techniques and copula modus-operandi. The objective of the paper is to find main reliability indexes such as availability of the system, reliability of the system, mean time to failure and expected profit. The results are shown in tables and graphs through which we establish the effect of failure rate and repair rate on reliability physiognomies. Lastly, the analysis of results indicates that copula repair is more effective in availability and expected profit analysis.