A multi-layered system of metrics for the measurement of reuse by inheritance

In spite of the intense efforts of metrics research, the impact of object-oriented software metrics is, for the moment, still quite reduced. The cause of this fact lies not in an intrinsic incapacity of metrics to help in assessing and improving the quality of object-oriented systems, but in the unsystematic, dispersed and ambiguous manner of defining and using the metrics. In this paper, we define a multi-layered system of metrics that measures inheritance-based reuse, and we propose a number of metric definitions for the layers of this system. By defining and using such systems of metrics, we obtain a unitary approach of related measures and a systematic, yet flexible manner of defining new measures as part of a particular metrics system. Organising metric definitions in systems of metrics contributes to (a strongly needed) order among object-oriented metrics, thus increasing their reliability and usability