IJAHP: Mu/About this special issue International Journal of the Analytic Hierarchy Process 309 Vol. 9 Issue 3 2017 ISSN1936-6744 https://doi.org/10.13033/ijahp.v9i3.554 About this Special Issue December 2017 Dear IJAHP Readers: We publish this issue still besieged by the sadness of the passing away of our founder and creator of the AHP methodology, Dr. Thomas Saaty –simply “Tom” for all of us who were lucky to work with him and to enjoy his collegiality and friendship. For this reason, this issue is dedicated to his memory and who better person to guest edit this special issue than Rozann Saaty, his close collaborator and lifelong companion. While Tom created AHP, Rozann was decisive in its diffusion worldwide through the Creative Decisions Foundation and her research on AHP validation. Rozann has worked long hours to edit this special issue in which several scholars, who worked closely with Tom, have selected their most memorable AHP papers. They will re-visit these articles and add their own insights and comments. Rozann, as guest editor, will provide the proper introduction to this special issue honoring Tom’s memory. Very sincerely, Enrique Mu, PhD IJAHP Editor-in-Chief