Visual Comparison of Graphical Models

Collaborative development, incremental design and revision management require the ability to compare different versions of software artifacts. There are well-established approaches for comparing textual artifacts such as program files. However, the situation is different in graphical modeling. So far there exists little support to compare models visually---graphically in the model diagram itself. This paper presents several possible approaches and explores one of these in further detail.We apply paradigms of visualizing text files side-by-side to graphical diagrams and enhance the views by additional features such as automatic layout, navigation and folding. These means allow to compare even complex models without missing differences or getting lost in text based structure compares.As a proof of concept, the proposal is implemented in KIELER, a prototypical modeling environment based on Eclipse.