The objective of this project is the modelling of a joint state classification that enables an assessment of interdependent multi-modal energy systems in terms of its (security-critical) functionalities. It will allow the identification and analysis of outages as well as failures (cascades) across multiple (multi-modal) domains of a system - i.e. electric, ICT, heat, gas. In this project the applicants will investigate this for the domains of first electric power systems with interconnections to gas and heat systems, and second ICT-systems including supervisory control and data acquisition and related communication. The first step of the project is to analyse blackouts regarding their interdependency of power and ICT-system. In a second step, classic system state classification in power systems (normal/N-1, alert, emergency, black out) will be detailed considering interconnections and interdependencies to other multi-modal energy systems. Outages and failures of primary equipment are the driving factors for state changes here. The interconnections to multi-modal energy systems will be considered and structured as outages. Especially common mode failures have to be investigated. Along these lines, system state classification will be done for the ICT-system considering the supervision, control and protection functions of power systems. This view focuses on the secondary equipment including control centres, but as well the future ICT on lower voltage levels below the transmission level. The next step combines both the extended power system state description and the ICT-state description into a integrated system state model. A formalized description of this model and the structure of the states and the criteria for the transition between them will be developed. Criteria for restoration paths will be specified along this framework. In the last step a risk analysis for the different states and the likelihood of their occurrence will be done. With such analysis planning, operation planning and operation criteria for ICT-reliant multi-modal energy systems are specified.