Restructuring Object -Oriented Designs Using a Metric-Driven Approach.

The benefits of object-oriented software are now widely recognized. However, methodologies that are used to develop object-oriented software are still in their infancy. There is a lack of methods to assess the quality of the various components that are derived during the development process. The design of a system is a crucial component derived during the system development process. Little attention has been given to assessing object-oriented designs to determine the goodness of the designs. There are metrics that can provide guidance for assessing the quality of the design. The objective of this research is to develop a system to evaluate object-oriented designs and to provide guidance for the restructuring of the design based on the results of the evaluation process. We identify a basic set of metrics that reflects the benefits of the object-oriented paradigm such as inheritance, encapsulation, and method interactions. Specifically, we include metrics that measure depth of inheritance, methods usage, cardinality of subclasses, coupling, class responses, and cohesion. We define techniques to evaluate the metric values on existing object-oriented designs. We then define techniques to utilize the metric values to help restructure designs so that they conform to predetermined design criteria. These methods and techniques are implemented as a part of a Design Evaluation Assistant that automates much of the evaluation and restructuring process