Studying the Relation BetweenChange- and Fault-proneness : Are Change-prone Classes MoreFault-prone, and Vice-versa?

Software is the heartbeat of modern technology. To keep up with the new demands and expansion of requirements, changes are constantly introduced to the software, i.e., changes can also be made to fix an existing fault/defect. However, these changes might also cause further faults/defects in the software. This study aims to investigate the possible correlation between change-proneness and fault-proneness in object- oriented systems. Forty releases of five different open-source systems are analysed to quantify change- and fault-proneness; Beam, Camel, Ignite, Jenkins, and JMe- ter, then statistic evidence is presented as to answer the following: (1) Is there is a relationship between change-proneness and fault-proneness for classes in object- oriented systems? (2) Is there a relationship between size and fault-proneness for classes in object-oriented systems? and (3) Is there a relationship between size and change-proneness for classes in object-oriented systems? Using the Wilcoxon rank- sum test, the results show that: (1) there is a correlation between change- and fault- proneness at a statistically significant level and (2) a correlation also exists betweenclass size and its change- and fault-proneness at a statistically significant level