Functional requirements identify the processes and information exchanges necessary to satisfy user needs. Requirements have already been allocated to functional objects, which is one reason why ARC-IT users are encouraged to jump from user needs to physical system architecture: requirements allocation has already been done. Nonetheless, new concepts may require some functional analysis, so the entirety of the functional view, including these requirements, is made available for extension.

Since requirements are allocated to functional objects, and since functional objects are included in service packages, requirements are organized and made viewable through those constructs. Requirements applicable to service packages (due to inclusion of functional objects in the service package) are displayed in the respective "needs and requirements" tab. Requirements are also viewable on the Functional Object detail pages.