A coverage based model for software reliability estimation

There is an increasing interest in estimating and predicting the reliability of software systems. Many models exist for reliability estimation. Most of these models consider a software system as a black box and predict the reliability based on the failure data observed during testing. The application of these models require a fair amount of data collection, computation, and expertise and computation for interpreting the results. We propose a model that is based on the coverage history of the program. A software is modeled as a graph, and the reliability of a node is assumed to be a function of the number of times it gets executed during testing-the larger the number of times a node gets executed, the higher its reliability. The reliability of the software system is then computed through simulation by using the reliabilities of the individual nodes. With such a model, coverage analysis tools can easily be extended to compute the reliability also, thereby fully automating reliability estimation.