After getting his PhD, he worked in the Department of Civil Engineering at Ohio State University as Assitant Professor from 1994 to 1996. From 1996 to 2003, he worked in the Department of Civil Engineering at Northwestern University, initially as Assistant and later as Associate Professor (Louis Berger Junior Chair). At the same time, he was affiliated with the Transportation Research Center and the Department of Industrial Engineering and Management Sciences of the same university. Since 2003, he has been with the Department of Mechanical Engineering, University of Thessaly, Volos, Greece, initally as Assocoiate Professor and currently as Professor of Optimization of Production/Transportation Systems and Head of the Systems Optimization Laboratory.