This level of architecture is defined in the common approach to Federal Enterprise Architecture Framework and focuses on one particular information technology system, which supports the delivery of one or more services within or between segments and agencies. All aspects of a system’s functionality and configuration should be documented, including strategic drivers, business requirements, applicable standards, workflow processes, information exchanges, software applications, host infrastructure, remote access, and security/privacy controls.

Source: See Federal Enterprise Architecture Framework (common approach - as explained in Collaborative Planning Methodology).