Old habits die hard: Why refactoring for understandability does not give immediate benefits

Depending on the context, the benefits of clean code with respect to understandability might be less obvious in the short term than is often claimed. In this study we evaluate whether a software system with legacy code in an industrial environment benefits from a “clean code” refactoring in terms of developer productivity. We observed both increases as well as decreases in understandability, showing that immediate increases in understandability are not always obvious. Our study suggests that refactoring code could result in a productivity penalty in the short term if the coding style becomes different from the style developers have grown attached to.