The terms interdependency and dependency are often used in the CIP literature as synonymous. See also dependency.
One of the most cited definitions of interdependency is the one by Rinaldi et al. who define interdependency as a
bidirectional relationship between two infrastructures through which the state of each infrastructure influences or is correlated to the state of the other .
This definition is adopted on the Commission's staff working document on a new approach to the EPCIP :
Interdependencies can be identified "between critical infrastructures, industry, and state actors". The working document also highlights that threats to a single Critical Infrastructure can have "a very significant impact on a broad range of actors in different infrastructures and more widely". The document also highlight the cross-border effect of interdependencies, spanning a number of European countries. The example identified in the document is the European high-voltage electricity grid, composed of the interconnected national high-voltage electricity grids.
Mutually reliant relationship between entities (objects, individuals, or groups) . The degree of interdependency does not need to be equal in both directions. For example, the Energy Sector depends on a functioning Water Sector for successful day-to-day operations, just as the Water Sector needs energy to effectively manage water and wastewater systems .
An older definition was:
Interdependency is the complete or partial mutual dependency of several goods or services .
Empirical analysis of events shows that interdependencies (mutual Dependency) hardly occur, and when they occur the effect is at a lower (weaker) dependency level.
- ↑ Steven M. Rinaldi, James P. Peerenboom, Terrence K. Kelly, Identifying, Understanding and Analysing Critical Infrastructure Interdependencies, IEEE Control Systems Magazine, December 2001, p.14.
- ↑ Staff Working Document on a new approach to the European Programme for Critical Infrastructure Protection - Making European Critical Infrastructures more secure, SWD(2013) 318 final, Brussels, 28.8.2013
- ↑ DHS Risk Lexicon 2010 Edition, September 2010
- ↑ Critical Infrastructure Protection and Resilience Toolkit (Glossary), US Department of Homeland Security
- ↑ http://www.kritis.bund.de/SharedDocs/Downloads/Kritis/EN/Baseline%20Protection%20Concept.pdf Protection of Critical Infrastructures – Baseline Protection Concept: Recommendation for Companies, BMI.
- ↑ Unpublished working glossary of UP KRITIS and BSI, 2014