Critical assets are pieces of equipment that are required to accomplish key processes. Identify each critical asset, the energy and/or water resources that the asset requires to operate, the key process(es) which it serves, , how long each key process can continue operation following asset disruption, and the amount of time needed to restart each key process once the asset resumes operating. All critical assets are assumed to be independent of each other. The STIR’s risk methodology assumes that the loss of a critical asset leads to the eventual complete loss of the associated key process.