Quality is a perceptual, conditional and somewhat subjective attribute and may be understood differently by different people. The reason for need of the software quality is of two reasons. Risk Management is the management of software failure that has caused more inconvenience. Cost Management is the management of cost that was due to the development of good quality software. One of the quality factors is Software Reliability. Reliability is usually defined as the probability that the system will operate without failure for a specified time under specified operating conditions is concerned with time between the failures or it's reciprocal. There are various software growth models available to predict the reliability of the software.