Severity Factor (SF): An aid to developers for application of refactoring operations to improve software quality

Abstract

Bad smells are certain flaws in the structure of the code that might not disturb the normal functioning of a program but negatively affects the software quality. Developers use refactoring as a corrective measure for the treatment of bad smells. The current study aids the developers in the application of refactoring by identifying the critical classes, that is, classes that are challenging to maintain and are of degraded quality. In this study, 10 quality metrics and 10 bad smells have been selected to conduct an investigation on different releases of five open‐source systems. A new metric, severity factor (SF) has been introduced that categorizes the classes of the selected systems into four criticality levels—severe, major, mid, and low. Also, the relationship between SF, criticality levels, and the refactoring operations has been analyzed. The findings show that 60% of the total classes have been affected by bad smells, and long statement is the most dominant smell present in 27.6% of the classes. The results show 84% of the refactoring operations have been performed on highly critical classes. Thus, the SF metric plays a crucial role in driving the developer's attention to the critical classes that need to be treated urgently.