Goal: Mitigate the danger of blackouts in communication and power supply networks Support of the “strategic assessment” of the current situation taking into account the dependency / interdependency structure. “Identified risks can be accepted or not with regard to the goal ?” Support of the “strategic decision making” based on the assessment of the current situation. Critical infrastructures (CIs) have undergone drastic changes in the last decades. The ubiquitous use of ICT has pervaded all traditional infrastructures, rendering them more intelligent, increasingly interconnected, complex, interdependent, and therefore more vulnerable. Critical infrastructures are vital backbones of modern societies and are increasingly depending on IT and communication networks. Due to the increasing IT-penetration CIs are more and more connected with each other with advantages and disadvantages. Due to this interconnection critical infrastructures can provide their services more cost-efficiently. On the other side in case of disturbances their behaviour can not ever be mastered as the large blackouts in USA and Europe have shown. Increasing complexity and manifold conventional and emerging threats jeopardise the system of mutual dependent critical infrastructures. CIP gains a high importance and has to be understood as a holistic process considering technologies and persons acting within this system of systems.