IRIS: a DSS for multiple criteria sorting problems

This paper presents Interactive Robustness analysis and parameters' Inference for multicriteria Sorting problems (IRIS), a Decision Support System (DSS) designed to sort actions (projects, candidates, alternatives, clients, etc.) described by their performances on multiple criteria into an ordered set of categories defined a priori. It is based on the ELECTRE TRI sorting method, but does not require the decision maker (DM) to indicate precise values for all of the method's parameters. More realistically, the software expects the DM to indicate some constraints that these parameters should respect, including sorting examples that the program should reproduce. If the constraints indicated by the DM do not contradict each other (i.e. form a consistent system), then IRIS infers a combination of parameter values that reproduces all the sorting examples, indicating also the range of possible assignments of actions to categories that would be possible without violating any of the stated constraints. If the constraints are contradictory (i.e. form an inconsistent system), then IRIS suggests a combination of parameter values that minimizes an error function and identifies alternative ways to restore the system's consistency by removing some constraints.