An Empirical Validation of Object Oriented Design Quality Metrics

This paper describes an integrated single class based metric called Weighted Class Complexity (WCC) for object oriented design. The metric is discussed from measurement theory viewpoint, taking into account the recognized object oriented features which the metrics was intended to measure encapsulation, inheritance, coupling and polymorphism, and the quality factors efficiency, complexity, understandability, reusability and maintainability/testability. Empirical data, collected from eight different application domains, is then analyzed using WCC metric to support this theoretical validation. The result shows that the proposed metric could be used to provide an overall quality assessment of object oriented software system in early stage of development life cycle, which may be helpful to the developer to fix problems, remove irregularities and non-conformance to standards and eliminate unwanted complexities in the early development cycle. Early use of this metric may help to ensure that the analysis and design have favorable internal properties that will lead to the development of quality end product. WCC may significantly help in reducing rework during and after implementation to design effective test plans. However, further studies are needed before these results can be generalized.