Cross-validation of Metrics for Software Components

The objective it to present a technique that facilitates cross-validation of software metrics for component-based development. The technique is illustrated with a cross-validation experiment for a suite of reusability metrics for component based design published in the literature. These metrics were originally proposed using a semi-formal notation, namely a combination of mathematical formulae with natural language descriptions for their elementary parts. They were then computed using proprietary tools. By contrast, we present a formalization for the metrics suite that combines the UML 2.0 metamodel with OCL. This technique provides a formal, portable and executable definition of the metrics set that can be used to perform cross-validations of the metrics suite, such as the one presented in this paper. The ability to independently replicate metrics validation experiments is essential to the scientific progress of component based software engineering.