Integrated technique assessment with imprecise information as a support for the identification of best available techniques

The determination of Best Available Techniques (BAT) plays an essential role in the realisation of the IPPC-Directive 96/61/EC (concerning integrated pollution prevention and control) in all Member States of the European Union. From a methodological point of view, the BAT determination is based on a comprehensive cross-media assessment of the impacts on the environment in general and therefore forms a multi criteria decision situation. However, exact data for the description of the investigated techniques and their potential environmental impact are rarely obtainable. Therefore, a decision support tool for the identification of BAT should also take into account imprecise information. In this paper, the Outranking method PROMETHEE has been chosen as a multi criteria decision support. Enhancements towards the consideration of imprecise information are discussed, such as fuzzy intervals and incomplete data sets. The application of the conceived multi criteria decision support tool as well as a graphical sensitivity analysis is presented with the help of a case study from the iron and steel making industry.