Decision making, whether by an individual or a group, can be substantially enhanced by a “systems thinking” approach. Because groups are often challenged to justify their decisions, it is necessary that they prepare themselves in advance for a possible challenge. We argue in this paper that this can to some extent be achieved through training the group in a “systems thinking” approach to decision making and using Toulmin’s schema of reasoning. The basis of our argument stems from observations made during the presentation of a new Masters module on Systems and Decision Making, conducted as a pilot study to form the basis for future field experiments.