CONTEXT : Many software architectural decisions are group decisions rather than decisions made by individuals. Consensus in a group of decision makers increases the acceptance of a decision among decision makers and their confidence in that decision. Furthermore, going through the process of reaching consensus means that decision makers understand better the decision (including the decision topic, decision options, rationales, and potential outcomes). Little guidance exists on how to increase consensus in group architectural decision making.
OBJECTIVE : We evaluate how a newly proposed process (named GADGET) helps architects increase consensus when making group architectural decisions. Specifically, we investigate how well GADGET increases consensus in group architectural decision making, by understanding its practical applicability, and by comparing GADGET against group architectural decision making without using any prescribed approach.
METHOD : We conducted two empirical studies. First, we conducted an exploratory case study to understand the practical applicability of GADGET in industry. We investigated whether there is a need to increase consensus, the effort and benefits of GADGET, and potential improvements for GADGET. Second, we conducted an experiment with 113 students from three universities to compare GADGET against group architectural decision making without using any prescribed approach.
RESULTS : GADGET helps decision makers increase their consensus, captures knowledge on architectural decisions, clarifies the different points of view of different decision makers on the decision, and increases the focus of the group discussions about a decision. From the experiment, we obtained causal evidence that GADGET increases consensus better than group architectural decision making without using any prescribed approach.
CONCLUSIONS : There is a need to increase consensus in group architectural decisions. GADGET helps inexperienced architects increase consensus in group architectural decision making, and provides additional benefits, such as capturing rationale of decisions. Future work is needed to understand and improve other aspects of group architectural decision making.