Operation-based conflict detection

In recent years, models are increasingly used throughout the entire lifecycle in software engineering projects. In effect, the need for collaboration and for management of change on these models emerged. Traditionally, Software Configuration Management (SCM) systems are employed to facilitate collaboration on software engineering artifacts and to control change to these artifacts. For scalability and to support offline operation, most of these systems employ optimistic concurrency control and therefore require methods to detect concurrent change---also known as conflict detection. However, many researchers have shown that existing approaches for SCM systems do not work well on graph-like models, since they are geared towards textual artifacts and do not take the graph structure of models into account. The approaches for conflict detection in these systems show many false positives, since they require a merge every time the same configuration item --- in this case the same file --- is changed. In this paper, we propose operation-based conflict detection, which detects conflicts directly on the operations that change the model. We compare operation-based conflict detection to file-based conflict detection in a multi-case study and show that operation-based conflict detection results in less conflicts and therefore requires fewer merges.