Assessing the impact of refactoring activities on the JHotDraw project

Refactoring is a well-known technique for improving the maintainability of software products. However, it is not easy to justify the time and effort needed to refactor code as the benefits are difficult to quantify, especially the perception of improved maintainability. In this paper, we highlight some results of a retrospective case study undertaken to shed light on how refactoring affects maintainability of a software product. There are several findings. First of all, refactoring affects the amount of subsequent changes. Furthermore, refactoring has a positive impact on the coupling relationships with dependent software applications.