Infrastructure Taxonomy: Common Terminology for Describing Critical Infrastructure

Overview

Critical infrastructure and key resources (CIKR) and their elements 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 uses an Infrastructure Taxonomy to enable transparent and consistent communication about CIKR between government and private sector partners. The Infrastructure Taxonomy 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 national CIKR.

With its structured terminology, the Infrastructure Taxonomy allows its 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.

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

Using the Taxonomy

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. By using the Infrastructure Taxonomy, the nuclear plant can be further categorized as demonstrated below:

• Sector: The nuclear plant is identified as being part of the Nuclear sector.
  • Sub-Sector: Within the nuclear sector, the nuclear plant is designated as part of the Nuclear Facilities 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 Liquid Metal Cooled Reactors sub-segment to recognize how the plant produces energy.

Background

The Infrastructure Taxonomy was first developed in 2005 and has since been revised through bi-yearly collaboration with the Sector-Specific Agencies (SSAs), the State, Local, Tribal and Territorial Government Coordinating Council (SLTTGCC), and private sector partners. The result of this collaboration is version three of the Infrastructure Taxonomy which is not only a robust system of categorization, but also a data requirements framework. Sectors have identified “attributes of interest” at different levels of the taxonomy, which can help focus data collection efforts.

Request the Taxonomy

The Office of Infrastructure Protection Infrastructure Information Collection Division (IICD) is responsible for the collaborative development and management of the Infrastructure Taxonomy. To request a copy of the Infrastructure Taxonomy or for additional information, please contact IICD at iicd@dhs.gov.