\input zb-basic \input zb-ioport \iteman{io-port 05607132} \itemau{Klein, R\"udiger} \itemti{Information modelling and simulation in large dependent critical infrastructures -- an overview on the European integrated project IRRIIS.} \itemso{Setola, Roberto (ed.) et al., Critical information infrastructure security. Third international workshop, CRITIS 2008, Rome, Italy, October 13--15, 2008. Revised papers. Berlin: Springer (ISBN 978-3-642-03551-7/pbk). Lecture Notes in Computer Science 5508, 131-143 (2009).} \itemab Summary: IRRIIS (``Integrated Risk Reduction of Information-based Infrastructure Systems'') is a European Integrated Project started in February 2006 within the $6^{\text{th}}$ Framework Programme and ending in July 2009. The aim of IRRIIS is to develop methodologies, models and tools for the analysis, simulation and improved management of dependent and interdependent Critical Infrastructures (CIs). Middleware Improved Technology (MIT) will provide new communication and information processing facilities in order to manage CI dependencies. This paper will give an overview of the IRRIIS project to outline these methodologies, models, and tools. Scenarios of depending CIs developed in IRRIIS are used to validate our approach and to demonstrate the usefulness of our results. \itemrv{~} \itemcc{} \itemut{critical infrastructures; dependability; CI dependency; information models; federated simulation; simulation environment; improved CI communication and management} \itemli{doi:10.1007/978-3-642-03552-4\_12} \end