An empirical study of the evolution of a software system

The cost-effective and reliable evolution of systems is a significant software engineering challenge. Our approach is based on a combination of product modelling, process modelling and software metrics. We describe an empirical laboratory study following the evolution of three releases of a publicly available exemplar system. Analysis of the metrics which were collected improves our understanding of how a system evolves. Process metrics can provide information about how the product is put together, and product metrics suggest explanations for the development processes observed.