ABSTRACT
Reliability is defined as the probability that a system or service will perform its intended function effectively for a specified period of time, or will operate in a defined environment without failure. In this chapter we provide the meaning, purposes and importance of reliability theory in the cloud system, and the entire work of reliability modeling with reference to discrete time is analyzed. Various reliability class distributions and their effects on cloud reliability are briefly discussed. An important aspect of the reliability block diagram is used to categorize the poor reliability of a cloud infrastructure, where enhancement can be made to lower the failure rate of the system. This technique can be used in the design and functional stages to determine poor reliability of a system and provide target improvements.
