Infrastructures: the CRUTIAL approach Giovanna Dondossola*, Fabrizio Garrone*, Marco Beccuti**, Giuliana Franceschinis** Silvano Chiaradonna*** Felicita Di Giandomenico***, Paolo Lollini*** Susanna Donatelli***** CRIS 2009 – Fourth International CRIS conference on Critical Infrastructures Linkoping, Sweeden, 28-30 Aprile 2009 * CESI RICERCA SPA ** UNIV. PIEMONTE ORIENT *** CNR-ISTI PISA **** UNIVERSITÀ DI TORINO In this paper we present the CRUTIAL approach to model and quantify (inter)dependencies between the Electrical Infrastructure (EI) and the Information Infrastructures (II) that implements the EI control and monitoring system. The quantification is achieved through the integration of two models: one that concentrates more on the structure of the power grid and its physical quantities and one that concentrates on the behaviour of the control system supported by the II. The modelling approach is exemplified on a scenario whose goal is to study the effects of a II partial failure (a denial of service attack that compromises the communication network) on the remote control of the EI.