Improving the Comprehension of Evolving Graphical Models

Context: Modeling industrial systems is mostly done collaboratively. In such a scenario, a model is modified by multiple people over a possibly long period of time. In consequence, modelers have to be able to understand a model’s evolution and, in particular, what elements of a model have changed, how, why, when, and by whom. Objective: We derive six distinct user goals and systematically design a graphical modeling languageagnostic set of tools that support users in achieving these goals. Method: We implement those tools and integrate them into an existing graphical modeling tool for technology roadmaps. To measure the tools’ usability, we conducted a mixed-methods study with participants of different levels of experience. With the set of developed tools at hand, in different scenarios, participants had to answer several questions regarding the evolution of a model. Results: The SUS score for assessing usability ranged from 80 to 95, indicating good to excellent usability. Task completeness (measured per scenario) ranged from 92% to 100%. Further, participants emphasized the added value of the tools while completing the scenarios. Conclusion: Although participants stated that the set of tools can be classified as expert tools, the developed tools achieve the goal of enabling users to comprehend changes made by others and trace the impacts of operations.