A new versioning approach for collaboration in blended modeling

The complexity of modern software-intensive systems and the need for flexibility in their development process forces developers to collaborate using the most appropriate language(s) for each given task, view and component. Blended modeling is the ability to edit a model through multiple concrete syntaxes simultaneously.

To support collaborative blended modeling, we present a variation of operation-based versioning that allows bi-directional propagation of changes between concrete and abstract syntaxes. This allows us to support layout continuity between different versions, and to handle information that is not (yet) available (e.g., layout information) when rendering changes from abstract to concrete syntax. Finally, our approach does not enforce immediate conflict resolution. Rather, different merge options and their consequences can be presented to the users, who may choose to only perform partial conflict resolution, deferring final resolution till later.

In this article, we present the general approach and describe salient parts of an implementation.