Robust multi-criteria sorting with the outranking preference model and characteristic profiles

• Method for multiple criteria sorting using outranking preference model.
• Decision classes defined with characteristic profiles and assignment examples.
• Reformulation of the Electre-Tri C assignment procedures.
• Analysis of necessary and possible assignments.
• Application to environmental risk assessment problem.

We present a new multiple criteria sorting approach that uses characteristic profiles for defining the classes and outranking relation as the preference model, similarly to the Electre Tri-C method. We reformulate the conditions for the worst and best class assignments of Electre Tri-C to increase comprehensibility of the method and interpretability of the results it delivers. Then, we present a disaggregation procedure for inferring the set of outranking models compatible with the given preference information, and use the set in deriving, for each decision alternative, the necessary and possible assignments. Furthermore, we introduce simplified assignment procedures and prove that they maintain a no class jumps-property in the possible assignments. Application of the proposed approach is demonstrated by classifying 40 land zones in 4 classes representing different risk levels.