On May 12, 2017, Raúl Pérez-Fernández successfully defended his Ph.D. thesis (cum laude) "Monotonicity-based consensus states for the monometric rationalization of ranking rules with application in decision making" at the Polytechnic School of Engineering of the University of Oviedo, Spain, and was awarded the joint degree of Doctor of Mathematics and Statistics (University of Oviedo) and Doctor of Applied Biological Sciences (Ghent University). The thesis was supervised by Bernard De Baets (KERMIT, Ghent University) and Irene Díaz and Susana Montes (University of Oviedo). This achievement represents a milestone in the longstanding cooperation between KERMIT and the University of Oviedo.