Evaluating Usefulness of Software Metrics: An Industrial Experience Report

A wide range of software metrics targeting various abstraction levels and quality attributes have been proposed by the research community. For many of these metrics the evaluation consists of verifying the mathematical properties of the metric, investigating the behavior of the metric for a number of open-source systems or comparing the value of the metric against other metrics quantifying related quality attributes. Unfortunately, a structural analysis of the usefulness of metrics in a real-world evaluation setting is often missing. Such an evaluation is important to understand the situations in which a metric can be applied, to identify areas of possible improvements, to explore general problems detected by the metrics and to define generally applicable solution strategies. In this paper we execute such an analysis for two architecture level metrics, Component Balance and Dependency Profiles, by analyzing the challenges involved in applying these metrics in an industrial setting. In addition, we explore the usefulness of the metrics by conducting semi-structured interviews with experienced assessors. We document the lessons learned both for the application of these specific metrics, as well as for the method of evaluating metrics in practice.