Visualizations to support interactive goal model analysis

While goals models can visually present alternate ways for achieving goals and how actors depend on each other, it can be challenging to follow the reasoning through complex paths in the model. In earlier studies which tested the utility of procedures for guiding analysts to perform interactive forward and backward reasoning through i* models, we uncovered several difficulties faced by study participants. Users often have trouble choosing suitable starting points for analyzing the model, and in understanding conflicts among alternatives. We have recently developed visualization mechanisms to alleviate these difficulties. Specifically, roots and leaves in the model are automatically detected and highlighted as suggested starting points for analysis. Goals within a conflicting path are highlighted during analysis. The visualization mechanisms were tested with users in five follow-up studies. The results suggest several further visualization mechanisms which could support analysis.