Can requirements dependency network be used as early indicator of software integration bugs?

Complexity cohesion and coupling have been recognized as prominent indicators for software quality. One characterization of software complexity is the existence of dependency relationship. Moreover, degree of dependency reflects the cohesion and coupling between software elements. Dependencies on design and implementation phase have been proven as important predictors for software bugs. We empirically investigated how requirements dependencies correlate with and predict software integration bugs, which can provide early estimate regarding software quality, therefore facilitate decision making early in the software lifecycle. We conducted network analysis on requirements dependency networks of two commercial software projects. We then performed correlation analysis between network measures (e.g., degree, closeness) and number of bugs. Afterwards, bug prediction models were built using these network measures. Significant correlation is observed between most of our network measures and number of bugs. These network measures can predict the number of bugs with high accuracy and sensitivity. We further identified the significant predictors for bug prediction. Besides, the indication effect of network measures on bug number varies among different types of requirements dependency. These observations show that requirements dependency network can be used as an early indicator of software Integration bugs.