Fuzzy sets and MCDM sorting

MCDM sorting methods have received a great deal of attention from practitioners and researchers. The development of the fuzzy extension of multi-criteria decision-making (MCDM) methods is increasing in sorting methods. This chapter introduces the basic concept of fuzzy sets to link this knowledge with the fuzzy extension of MCDM methods. The fuzzy set is widely used in MCDM and hence in the sorting methods for different purposes related to data and processes. The chapter also details the interesting use of fuzzy numbers in different processes related to MCDM, such as to elicit experts' preferences, to define limiting or central profiles, and to develop fuzzy sorting procedures.