An Object-Oriented Metric To Measure The Degree Of Dependency Due To Unused Interfaces

Object-Oriented frameworks are sets of classes designed to work together in order to offer generic solutions to many specific problems within the same application domain. A situation that often arises from the design of a framework is the interface dependency problem produced by interface inheritance when subclasses do not really need the interfaces. This problem negatively affects frameworks in their reuse and extension qualities. Although we know that this problem exists, we do not have a way to measure to what extent this problem affects frameworks. In this paper an object-oriented metric to measure the degree of dependency due to unused interfaces is proposed. Case studies are presented in order to show how this metric helps to detect when frameworks have a serious interface dependency problem. With this information a quantitative decision can be made to take care of the problem.