Object-Oriented Programming Metrics Measurement Quality Analysis and Evaluation
Institute of Information Theories and Applications FOI ITHEA
Metrics estimate the quality of different aspects of software. In particular, cohesion indicates how well
the parts of a system hold together. A metric to evaluate class cohesion is important in object-oriented
programming because it gives an indication of a good design of classes.
There are several proposals of metrics for class cohesion but they have several problems (for instance, low
discrimination). In this paper, a new metric to evaluate class cohesion is proposed, called SCOM, which has
several relevant features. It has an intuitive and analytical formulation, what is necessary to apply it to large-size
software systems. It is normalized to produce values in the range [0..1], thus yielding meaningful values. It is also
more sensitive than those previously reported in the literature. The attributes and methods used to evaluate
SCOM are unambiguously stated. SCOM has an analytical threshold, which is a very useful but rare feature in
software metrics. We assess the metric with several sample cases, showing that it gives more sensitive values
than other well know cohesion metrics.