Toward the Design Quality Evaluation of Object-Oriented Software Systems

This paper presents some advances towards the quantitative evaluation of design attributes of object-oriented software systems. We believe that these attributes can express the quality of internal structure, thus being strongly correlated with quality characteristics like analyzability, changeability, stability and testabilility, which are important to software developers and maintainers. An OO design metrics set is reviewed, along with its rationale. An experiment for collection and analysis of those metrics is described and several suppositions regarding the design are evaluated. A considerable number of class taxonomies written in the C++ language were used as a sample. A tool to collect those metrics was built and used for that purpose. Statistical analysis was performed to evaluate the collected data. Results show that some design heuristics can be derived and used to help guide the design process. It was also clear that a number of follow-up topics deserve further research.