Rodolfo Soncini-Sessa received his PhD on System Analysis at Politecnico di Milano, Italy in 1972; he was with the Water Group of the International Institute for System Analysis (IIASA) several times since 1975 and thought Water Management in some Italian Universities before being full professor of Natural Resources Management at the Politecnico di Milano. He is chair of the IFAC TC on Modelling & Control of Environmental Systems, and in the Editorial Boards of Water International and Journal of Environmental Modelling and Software. His main research interests are in the design of DSS for participatory decision making in the area of water resources.Andrea Castelletti received a MS degree in Environmental Engineering and a PhD in Information Engineering from Politecnico di Milano, Italy, in 1999 and 2005. He is Assistant Professor of Modelling and Control of Environmental Systems in the same university. His main research interests focus on modelling and control of water resource systems and Decision Support System design.