The semi-Markov process and regenerative point technique are adopted to obtain reliability measures of a computer system by providing software redundancy in cold standby. Initially, hardware and software work together in the system which may fail independently with some probability. There is a single server who repairs the system at hardware failure while software is up-graded as per requirements. The repair and up-gradation activities are performed perfectly and efficiently by the server. The time to hardware and software failures follows negative exponential distribution, whereas the distributions of hardware repair and software up-gradation times are taken as arbitrary with different probability density functions. Graphs are drawn to depict the behaviour of some important performance and economic measures of the system model for arbitrary values of various parameters and costs.
Computer System, Software Redundancy, Reliability Measures and Stochastic Model
