Do Internal Software Metrics Have Relationship with Fault-proneness and Change-proneness?

Fault-proneness is a measure that indicates the possibility of programming errors occurring within a software system. On the other hand, change-proneness refers to the potential for modifications to be made to the software. Both of these measures are crucial indicators of software maintainability, as they influence internal software metrics such as size, inheritance, and coupling, particularly when numerous changes are made to the system. In the literature, research has predicted change- and fault-proneness using internal software metrics that is almost a decade old. However, given the continuous evolution of software systems, it is essential to revisit and update our understanding of these relationships. Therefore, we have conducted an empirical study to revisit the relationship between internal software metrics and change-proneness, and faultproneness, aiming to provide current and relevant insights. In our study, we identified 25 internal software metrics along with the measures of change-proneness and fault-proneness within the wellknown open-source systems from the Apache and Eclipse ecosystems. We then analyzed the relationships between these metrics using statistical correlation methods. Our results revealed that most of the metrics have little to no correlation with fault-proneness. However, metrics related to inheritance, coupling, and comments showed a moderate to high correlation with change-proneness. These findings will assist developers to minimize the higher correlated software metrics to enhance maintainability in terms of change- and fault-proneness. Additionally, these insights can guide researchers in developing new approaches for predicting changes and faults by incorporating the metrics that have been shown to have stronger correlations.