Understanding and Using the Group Decision Analysis Model

Decision analysis is usually thought of as a model for decisions with a single decision-maker. Many attempts to extend decision analysis to group decisions have led to results indicating how it cannot be done. Other analyses, such as the well-known impossibility theorem of Arrow (1963) [1], have tried to combine rankings of alternatives by individual group members to produce a group ranking. As a result, there had been no logically consistent way to extend the principle of decision analysis to group decisions. A different approach was used in Keeney (2013), where each member of a decision-making group could have a different decision frame for their common decision. Using the assumptions of decision analysis for each member’s analysis of their group decision and using an analogous set of decision analysis assumptions for the group decision to combine the member’s decision analyses produced a group decision analysis model. This article discusses the concepts and intuitive logic for the model and practical aspects of applying it.