SV-4 Systems Functionality Description

Description

The SV-4 addresses human and system functionality.

The primary purposes of SV-4 are to:

• Develop a clear description of the necessary data flows that are input (consumed) by and output (produced) by each resource.
• Ensure that the functional connectivity is complete (i.e., that a resource’s required inputs are all satisfied).
• Ensure that the functional decomposition reaches an appropriate level of detail.

The Systems Functionality Description provides detailed information regarding the:

• Allocation of functions to resources.
• Flow of resources between functions.

The SV-4 is the Systems Viewpoint model counterpart to the OV-5b Activity Model of the Operational Viewpoint.

The intended usage of the SV-4 includes:

• Description of task workflow.
• Identification of functional system requirements.
• Functional decomposition of systems.
• Relate human and system functions.

Implementation

SV-4 can be represented using:

• A SV-4 diagram for System Function hierarchies. This diagram is based on the UML Class diagram.
  
• An SV-4 diagram for System Function flows. This diagram is based on the UML Activity diagram.
  
• A UML Class diagram.
• A UML Activity diagram.
• A SysML Block diagram.
• A SysML Activity diagram.

The SV-4 is the behavioral counterpart to the SV-1 Systems Interface Description (in the same way that  OV-5b Operational Activity Model is the behavioral counterpart to  OV-2 Operational Resource Flow Description).