Estimating the size of changes for evolving object oriented systems: a case study

Size related measures have traditionally been the basis for effort estimation models to predict costs of software activities along the entire software product life cycle. Object-Oriented (OO) systems are developed and evolve by adding/removing new classes and modifying existing entities. We propose an approach to predict the size of changes of evolving OO systems based on the analysis of the classes impacted by a change request. Our approach can be used both in iterative development processes or during software maintenance. A first empirical evaluation of the proposed approach has been obtained by applying our tools to the post-release evolution of OO software systems available on the net. The systems were analyzed, and models to predict added modified LOCs from added/modified classes were statistically validated. In the paper preliminary results of the above outlined evaluation is presented