Much of the work that has been done in the last fifty years in the area of decision analysis has been concerned with situations in which formal mathematical models of the decision process can be used. For example, deterministic models of operations research have been used as a means of treating decisions under conditions of certainty. Statistical decision theory has been applied to decision making under conditions of uncertainty and risk. Some attempts have been made to treat decisions under conditions of competition by methods derived from game theory. However, many of the decisions that we meet today in business and in our daily lives do not fall conveniently into the areas covered by these models. Many modern decisions are ill-structured by nature. These decisions have been called ''wicked" in comparison to the "tame" decisions that yield to formal analyti­ cal treatment. Complex decision situations are found in every aspect of our lives today. They are normally centred around an issue, opportunity, venture or threat that involves an individual or an organization on the one hand and other participants on the other hand. The issue in such a situation might involve, for example, the proposed move of the Head Office of a corporation from one political jurisdiction to another. It might be concerned with the oppor­ tunities and new ventures that would arise with the introduction of a new and different type of product or service into an organization.