How Humans Merge UML-Models

So far, research on model merging has mostly focused on algorithmic problems. But, there are various situations when software engineers have to compare and merge different models manually or at least make important decisions. In this paper, we provide insights into the process of how users compare and merge visual models. To this end, we observed people´s activities when manually merging UML class diagrams and analyzed the recorded data following the Grounded Theory approach. To illustrate the usefulness of our results we derived some guidelines for tool design.