Résumé : The paper presents the elements of a new methodology to control complex and hypercomplex socio-economic structures. The control process is iterative, combining the principles of System Dynamics, Control theory and the PROMETHEE Multicriteria Decision Aid (MCDA) methodology. It consists of three main stages: setting up and calibration of a quantitative model, definition of long-term strategies and short-term control. The purpose is to define within a panel of decision makers appropriate strategies towards long-term goals, and to implement suitable control measures. These should in particular help cope with progressive and catastrophic variations in the behaviour of the system. © 1998 Published by Elsevier Science B.V. All rights reserved.