Opportunities and challenges in deriving metric impacts from refactoring postconditions

Refactoring – transforming the source-code of an object-oriented program without changing its external observable behaviour – is a restructuring process aimed at resolving evolution obstacles. Currently however, the efficiency of the refactor process in terms of quality improvements remains unclear. Such quality improvement can be expressed in terms of an impact on OO metrics. The formalization of these metrics is based on the same constructs as refactoring postconditions. Therefore, in this position paper, we elaborate on a research approach to derive Object-Oriented metric impacts from refactoring postconditions, in order to provide qualitative guidelines on the application of specific refactorings to resolve quality deficiencies.