On the Diverse Uses of Multiple Criteria Decision Aiding Tools in Complex Decision Problems

ABSTRACT Several multicriteria methods have been created for use in problem situations that are considered complex because multiple actors and/or organisations are involved. Such methods are easily combined with problem shaping and structuring methods to reduce complexity when a situation is new, ill‐ or not well‐structured. These situations can also be dealt with by resorting to multiple criteria decision aiding MCDA approaches that use certain tools. Such tools are not only multicriteria methods but also logical and analytical models, interactive procedures and critical analyses of method results, which can be directly oriented towards activating mutual learning processes. Indeed, combining multicriteria methods with other tools, which are oriented more towards posing a decision problem than to solving it, can aid the perception and description of the nature and complexity of the situation in the initial phase of a decision aid process, orient a decision aid intervention and improve its effectiveness. An easy visualisation and understandability of the model components, of the used data and of the method application results facilitate a critical revision of the original problem formulation and modelling, and they can activate steps of mutual learning, improvements of the model and results, and of the generation of robustness, not only of the results but also of the model, and the decision and decision aid processes. This interpretation of how an integration of MCDA models, methods and other tools can be used to deal with complex decision problems is not new. Bernard Roy called this approach MCDA ‘description problematic’, but this methodological approach is rarely put into practice and still needs conceptual definition and structural clarity. An analysis framework is here presented to distinguish between some different MCDA situations where the outranking methods are oriented towards a description problem statement. Two complex cases are proposed to describe the main characteristics of four situations, which influence an analyst's behaviour and decision aid results, and suggest that some multicriteria models and methods should be used in complex situations first and foremost to facilitate understanding and communication.