Group decision analysis based on fuzzy preference relations: Logarithmic and geometric least squares methods

Logarithmic and geometric least squares methods (LLSM and GLSM) are, respectively, applied to deal with the group decision analysis problems with fuzzy preference relations, where multiplicative preference relations, if any, are transformed into fuzzy preference relations through proper transformation technique. Distance between any two fuzzy preference relations and the average distance from one fuzzy preference relation to all the others are defined and used to measure the relative importance of each fuzzy preference relation. A numerical example involving multiple fuzzy and multiplicative preference relations is examined using the proposed methods. It is shown that LLSM and GLSM provide two analytical and effective ways of modelling multiple fuzzy preference relations.