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Homeland Security

Infrastructure Data Taxonomy: Common Terminology for Describing Critical Infrastructure


Critical infrastructure can be described and categorized in various ways, which can result in inconsistent communication and hinder timely decision-making within the homeland security community.

To prevent such problems, the Department of Homeland Security created the Infrastructure Data Taxonomy to facilitate a common understanding of infrastructure terminology within the critical infrastructure protection community. The Taxonomy is used to categorize infrastructure assets and establishes a common language for all to use. It also facilitates more efficient data integration and transfer of information between systems; thus, it is the foundation for multiple Department tools and systems that focus on the identification, collection, sharing, and cataloguing of the nation’s critical infrastructure.

By applying a detailed, structured system of categorization to assets that includes sectors, sub-sectors, segments, sub-segments and asset type, the Infrastructure Data Taxonomy minimizes potential confusion and enhances transparency about critical infrastructure.

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How Is The Infrastructure Data Taxonomy Used?

With its structured terminology, the IDT allows users to designate an asset as belonging to a particular group, and then apply additional associated taxonomy levels to detail the specifics of the asset and describe its functions.

For example, the government and private sector may refer to a specific nuclear plant as a nuclear plant, a nuclear site or a nuclear facility. The example below shows how a specific nuclear facility would be classified using the Infrastructure Data Taxonomy:

  • Sector: The nuclear plant is identified as being part of the Nuclear reactors, Materials, and Waste sector.

    • Sub-Sector: Within the Nuclear Reactors, Materials, and Waste sector, the nuclear plant is designated as part of the Nuclear Facility sub-sector.
      • Segment: The nuclear plant is identified as part of the Nuclear Power Plant segment to recognize the plant’s purpose.
        • Sub-Segment: Finally, the nuclear plant can be categorized as being part of the Boiling Water Reactor sub-segment to recognize how the plant produces energy.

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How Is the Infrastructure Data Taxonomy Generated?

The Infrastructure Data Taxonomy was first developed in 2005 and is the result of ongoing collaboration with the Sector-Specific Agencies; the State, Local, Tribal, and Territorial Government Coordinating Council; and private sector partners through the Infrastructure Data Taxonomy Working Group. The result of this collaboration is version four of the Infrastructure Data Taxonomy, which serves both as a system of categorization and a data standard.

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Who Uses the Infrastructure Data Taxonomy?

Although not mandatory, the Taxonomy is now widely used by homeland security partners, including other federal agencies and states, to facilitate information sharing and interoperability.

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How to Access the Infrastructure Data Taxonomy

Request access to the Infrastructure Data Taxonomy.  To login to download, view and comment on the IDT, click here.

The Infrastructure Information Collection Division (IICD) within the Office of Infrastructure Protection is responsible for the collaborative development and management of the Infrastructure Data Taxonomy.

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Last Published Date: February 28, 2013
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