Considering Fault Correction Lag in Software Reliability Modeling

The fault correction process is very important in software testing, and it has been considered into some software reliability growth models (SRGMs). In these models, the time-delay functions are often used to describe the dependency of the fault detection and correction processes. In this paper, a more direct variable "correction lag", which is defined as the difference between the detected and corrected fault numbers, is addressed to characterize the dependency of the two processes. We investigate the correction lag and find that it appears Bell-shaped. Therefore, we adopt the Gamma function to describe the correction lag. Based on this function, a new SRGM which includes the fault correction process is proposed. And the experimental results show that the new model gives better fit and prediction than other models.