This level of architecture is defined in the common approach to Federal Enterprise Architecture Framework and provides an overview of the entire department/agency and consistent, decomposable views of all sub-agencies/bureaus, business units, programs, systems, networks, and mission or support services. The depth of documentation in any particular area of an agency’s architecture is determined by the need to support planning and decision-making, prioritized in the context of the agency’s strategic goals and business operating plans. Drill-down is accomplished through the completion of segment, system, and application-level architectures.

Source: See Federal Enterprise Architecture Framework (common approach).