Aid for aggregating the impacts in Life Cycle assessment

Abstract

Multiple Criteria Decision Aid (MCDA) methods may be employed in a great number of fields. Life Cycle Assessment (LCA) is a specific method among the MCDA Methods. A stage of MCDA methods to be respected in LCA is the comparative evaluation of the environmental impacts. This stage is the most difficult to implement because it is a question of estimating the global environmental impact of the life cycles studied. To achieve this purpose, it is necessary to model the environmental impacts and to apply a Multicriteria Analysis (MCA) method. The problem is to choose the most suitable among the available MCA methods. The objective of this paper is to help the LCA practitioner to make this choice. The MCA methods are compared according to their non-compensatory degree, their sensitivity to thresholds, their practicability and their workability. The protocol presented in this paper allows to choose the most appropriate MCA method for a given LCA according to the four previous criteria. This choice will depend on the priorities of the decision maker with concern to the comparison criteria.