Extending and Managing Software Reflexion Models

The artifacts comprising a software system often "drift" apart over time. Design documents and source code are a good example. The software reflexion model technique was developed to help engineers exploit---rather than remove---this drift to help them perform various software engineering tasks. More specifically, the technique helps an engineer compare artifacts by summarizing where one artifact (such as a design) is consistent with and inconsistent with another artifact (such as source). The use of the technique to support a variety of tasks-including the successful use of the technique to support an experimental reengineering of a system comprising a million lines-of-code-identified a number of shortcomings. In this paper, we present two categories of extensions to the technique. The first category concerns the typing of software reflexion models to allow different kinds of interactions to be distinguished. The second category concerns techniques to ease the investigation of reflexion models. These extensions are aimed at making the engineer more effective in performing various tasks by improving the management and understanding of the inconsistencies---the drift---between artifacts.