To manage critical infrastructure risk effectively, partners must identify the assets, systems and networks that are essential to their continued operation, considering associated dependencies and interdependencies. This aspect of the risk management process also should identify information and communications technologies that facilitate the provision of essential services.

Critical infrastructure partners view criticality differently, based on their unique situations, operating models and associated risks. The Federal Government identifies and prioritizes nationally significant critical infrastructure based upon statutory definition and national considerations. SLTT governments identify and prioritize infrastructure according to their business and operating environments and associated risks. Infrastructure owners and operators identify assets, systems and networks that are essential to their continued operations and delivery of products and services to customers. At the sector level, many SSAs collaborate with owners and operators and SLTT entities to develop lists of infrastructure that are significant at the national, regional and local levels.

Effective risk management requires an understanding of criticality as well as the associated interdependencies of infrastructure. This National Plan identifies certain lifeline functions that are essential to the operation of most critical infrastructure sectors. These lifeline functions include communications, energy, transportation and water. Critical infrastructure partners should identify essential functions and resources that impact their businesses and communities. The identification of these lifeline functions can support preparedness planning and capability development.