Availability modelling and enhancement of a computer system with redundant heteregeneoud software

Abstract

This paper studies the availability of one host system incorporating heterogeneous software in the host.  The system has two types of heterogeneous software. Each type of software has an identical copy (homogeneous) on standby. Markov model of the system is derived through the system state transition probabilities and the corresponding differential difference equations are used to evaluate the system availability. Comparison of the availability for different values of hardware failure and repair rate are performed and found that availability is higher with low hardware failure rate and higher repair rates.