Considering fault dependency and debugging time lag in reliability growth modeling during software testing

Since the early 1970's tremendous growth has been seen in the research of software reliability growth modeling. In general, software reliability growth models (SRGMs) are applicable to the late stages of testing in software development and they can provide useful information about how to improve the reliability of software products. For most existing SRGMs, most researchers assume that faults are immediately detected & corrected. However, in practice, this assumption may not be realistic and satisfied. In this paper we first give a review of fault detection and correction processes in SRGMs. We show how several existing SRGMs based on NHPP models can be comprehensively derived by applying the time-dependent delay function. Furthermore, we will show how to incorporate both failure dependency and time-dependent delay function into software reliability growth modeling. We present stochastic reliability models for software failure phenomenon based on NHPPs. Some numerical examples based on real software failure data sets are presented. The results show that the proposed framework to incorporate both failure dependency and time-dependent delay function into software reliability modeling has a useful interpretation in testing and correcting the software.