Two Complexities and a Few Models

The difficulty in dealing with urban systems’ complexity and the related difficulty to analyse and forecast is twofold: one kind of difficulty lies in the complexity of the system itself, and the other is due to the actions of actors, which are “acts of freedom”. In our contribution we would like to present a set of techniques and models, with respective software packages (MaGIA, The Time Machine, CAGE and GioCoMo), that have proven to be of great potential for enactment and management of communication, participatory, consensus-building and simulation processes. As such, our approach tries to cope with both aspects of complexity mentioned above.