Group Decision Support for Crop Planning: A Case Study to Guide the Process of Preferences Elicitation

The land of Paggaio, Kavala, Greece although very rich, has been cultivated in ways that affected both local environment and economies disadvantageously giving rise to the crucial problem of strategic crop planning. However, because of the many actors involved, and of their conflicting interests, reaching a consensus about what the objectives of such a planning should be, is a complex and challenging task. So as a first, preparatory step for strategic crop planning, the interested parties should acquire a clear view about what are the differences in the preferences of the involved actors. In this chapter, we present the steps that we followed in order to execute an end-to-end process for a client that needed to unveil what are the criteria that guide the preferences of the actors and which actors converge (or diverge) the most, with respect to the evaluation on these criteria. Following a prescriptive approach (that assumes that a preference model exists), we sketched the relevant problem situation and problem formulation, constructed an evaluation model based on a multiple criteria technique, and eventually reached some recommendations. The case study we present in this work could help analysts to structure their own decision aid processes based on an established roadmap, as well as to become aware of the process pitfalls. Regarding the referenced case study, it showed that actors have strongly diverging preferences, so that it was not possible to discover a robust collective model. However, we were able to identify the points of major conflict in two criteria (environmental friendliness and economical performance) and amongst certain stakeholders.