Wiki of Accidents Consequences Group

Input-output inoperability model (IIM) is a mechanism for analyzing the cascading effects induced by critical infrastructure dependencies and interdependencies. This paper proposes a methodology for evaluating IIM parameters based on technical and operational data.

IIM focuses on the spread of operability degradation in a networked system. In particular paper described methodology “engages subjective information about infrastructure dependencies for the purpose of critical infrastructure analysis and risk management. The subjective information is obtained from domain experts and aggregated using fuzzy numbers, enabling the assessment of the effects on infrastructures induced by direct and higher­order dependencies.”

The application of the methodology is demonstrated on Italian national infrastructure. The dependencies existing between eleven sectors in the Italian critical infra­structure are analyzed:

1 Air Transportation

2 Electricity

3 Wired Telecommunications (TLC Wired)

4 Wireless Telecommunications (TLC Wireless)

5 Water Management

6 Rail Transportation

7 Finance

8 Naval Ports

9 Fuel & Petroleum Grid

10 Natural Gas

11 Satellite Communication & Navigation