A system of computer with Preventive maintenance over H/w and S/w subject to maximum operation time

This paper analyzed a system of computer with component-wise redundancy with independent failures of software and hardware. There are two units-one primarily operative and other reserved as hardware cold standby. After determined operation time, by conducting precautionary conservation of hardware unit, there are two possibilities that is operative unit undergoes for software up gradation with some probability while other possibility for hardware unit after independent failures. A single server is available instantly to provide the services like repairs of hardware, software components and preventive maintenance. The system is in good state after repair. The different failures of system follow exponential distribution whereas others are arbitrary. Regenerative Point Graphical Technique (RPGT) with semi-Markov process is used for finding the consistency and other strictures of the system speedily and easily. The derived expressions like mean time to system failure (MTSF), availability of the system, different busyness of system and the number of visits of the server are shown graphically.