Large scale crises are affecting critical infrastructures with a growing frequency. This is a result of both basic exposure and dependencies between infrastructures. Because of prohibitive costs, the paradigm of protection against extreme events is expanding and now also encompasses the paradigm of resilience. In addition to strengthening and securing systems; system design objectives are now being set, and response planning is being carried out, to facilitate a fast recovery of infrastructure following a large scale incident.

With an interconnected European society, countries and infrastructures are increasingly reliant upon their neighbours, both under normal operating conditions and in the event of an incident. Despite this, there is no common European methodology for measuring resilience or for implementing resilience concepts, and different countries and sectors employ their own techniques. There is also no shared, well-developed system-of-systems approach, which would be able to test the effects of dependencies and interdependencies between individual critical infrastructures and sectors. This increases the risk as a result of reliance on critical infrastructures, as well as affects the ability for sharing resources for incident planning due to no common terminology or means of expressing risk.