We report on an recent European Project aimed at assessment of suited Methodologies to measure interdependencies between the Electric and the ICT System. Based on best practices and available data, several different metrics have been defined. Depending on the methodology involved, three main types of metrics can be identified; namely "topological"; "system theory based" and "simulation based" metrics. The selected methodologies have been applied to the Roma Area electric and communication system. Results from all the different approaches are discussed. All metrics provide quantitative measures of the inter-dependence between both the two systems and their components. In addition to the established metrics, a novel "spectral" metric has been introduced specific for cascade effects. Such an innovative methodology has also been applied to the US Power Grid and results compared with those from the Roma Area. © 2010 IEEE.