Scenario generation and reduction in the decision support system GMCR II

The most difficult environmental decision problems usually involve a range of interest groups, each with different preferences with respect to scenarios, or possible states of the interaction. The graph model for conflict resolution was designed to study systematically strategic conflicts that can arise in environmental management and elsewhere. A new decision support system called GMCR II is being developed to enable practitioners to apply the graph model for conflict resolution conveniently and expeditiously. At the model building stage of GMCR II, it is often useful to represent a conflict in option form, which structures the model by specifying the decision-makers (DMs), the courses of action or options available to each DM, and each DM´s preferences. If there are m options in the model, there are 2^m mathematically possible states. Usually, however, many of the possible option combinations cannot occur in practice and therefore must be eliminated from the model. The design of GMCR II´s user-friendly interface and the efficient algorithms it uses to eliminate infeasible states are presented. In addition, all states in a group of essentially equivalent states can be readily combined into one using other built-in procedures. An environmental management dispute is used to illustrate the application of GMCR II