Qualitative multicriteria methods for fuzzy evaluation problems: An illustration of economic–ecological evaluation

It is nowadays increasingly realised that environmental and resource problems generally have complicated economic and ecological dimensions. Therefore, there is a clear need for models offering a comprehensible and operational representation of a real-world environmental system. A great variety of quantitative (descriptive and forecasting) models has been developed for compound environmental systems, but there is still a need in a planning context for evaluation methods taking into account information of a mixed (qualitative and quantitative) type. This paper presents a new discrete multicriteria evaluation model whose impact (or evaluation) matrix may include either crisp, stochastic or fuzzy measurements of the performance of an alternative an with a respect to a criterion gm. No traditional weighting of criteria is used in this method. From an empirical point of view, this model is particularly suitable for economic–ecological modelling incorporating various degrees of precision of the variables measured. From a methodological point of view, two main issues will be faced here: (i) the problem of equivalence of the used procedures in order to standardise the various evaluations (of a mixed type) of the performance of alternatives according to different criteria; (ii) the problem of comparison of fuzzy numbers typical of all fuzzy multicriteria methods. An illustrative numerical example will be presented at the end of the paper.