Software reliability is generally a key factor in software quality. Reliability is an essential ingredient in customer satisfaction. In software development process reliability conveys the information to managers to access the testing effort and time at which software release into the market. Large numbers of papers are published in this context. In this paper we proposed a software reliability growth model with generalized modified weibull testing effort. Performance application of proposed model is demonstrated through real datasets. The experimental results shown that the model gives an excellent performance compared to other models. We also discuss the optimal release time based on reliability requirement and cost criteria.