Reliability Modeling of A Cloud System with Independent H/W and S/W Failure Subject to Maximum Operation and Repair Times with Regenerative Point Technique

In this paper reliability and economic measures of a cloud system having independent h/w and s/w failure. For this purpose, a reliability model is developed considering cloud system as a single unit. A perfect server is provided to do preventive maintenance, repair and replacement of the components upon their failures immediately, can not leave the system during job. After a maximum operation time the unit undergoes for preventive maintenance directly from normal mode. If repair of the component is not possible up to a pre-specific time (called Maximum Repair Time), the components are replaced by new one with some replacement time. However, only replacement of the software components by new one is made after failures. The failure time of the components follow negative exponential distribution, while the distributions of preventive maintenance, repair and replacement time are taken as arbitrary with different probability density functions. The switches are perfect. Various reliability indices are obtained using semi-Markov process and regenerative point technique. Graphs are drawn for a particular case to depict the behavior of MTSF, availability and profit function.