Within an Architectural Description, the SvcV-4 “Services Functionality Description” documents service functions, the Resource Flows between those service functions, the internal system data repositories or service data stores, and the external sources and sinks for the service data flows, but not external to the Architectural Description’s scope. They may also show how users behave in relation to those services. The primary purpose of SvcV-4 is to: 
- Develop a clear description of the necessary data flows that are input (consumed) by and output (produced) by each resource
- Ensure that the service 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 Services Functionality Description provides detailed information regarding the: 
- Allocation of service functions to resources
- Flow of resources between service functions
- The SvcV-4 is the Services Viewpoint counterpart to the OV-5b Operational Activity Model of the Operational Viewpoint (OV)
The intended usage of the SvcV-4 includes: 
- Description of task workflow
- Identification of functional service requirements
- Functional decomposition of Services
- Relate human and service functions
It is important to note that one usage of the SvcV-4 can support a net-centric (service oriented) implementation in describing the producing services and consuming services. The Services Functionality Description information can support the registration of services in netcentric (service-oriented) implementation.
The SvcV-4 is used to specify the service functionality of resources in the architecture. The SvcV-4 is the behavioral counterpart to the SvcV-1 “Services Context Description” (in the same way that OV-5b Operational Activity Model is the behavioral counterpart to OV-2 “Operational Resource Flow Description”).
The scope of this model may be capability wide, without regard to which resources perform which service functions, or it may be resource-specific. Variations may focus on intra- or inter-resource data flows, or may simply allocate service functions to resources.
There are two basic ways to depict a SvcV-4: 
- The Taxonomic Service Functional Hierarchy shows a decomposition of service functions depicted in a tree structure and is typically used where tasks are concurrent but dependent, such as a production line, for example.
- The Data Flow Diagram shows service functions connected by data flow arrows and data stores
|DoDAF Viewpoint Matrix|
- The DoDAF descriptions in this website are very generic and are mostly taken from the DoDAF Architecture Framework website. Make sure you visit the actual website for the most update information and a more thorough explanation of each viewpoint.
- DoDAF Version 1.0, although outdated, has some good examples on how to construct AV’s, OV’s, and SV’s.
AcqLinks and References:
-  DoDAF Architecture Framework Version 2.02
- DoD Architecture Framework Working Group Version 1.0, Volume 1: Definition and Guideline, 9 Feb 04 (Old Version)
- DoD Architecture Framework Version 1.0, Volume 2: Product Description, 9 Feb 04 (Old Version)
- Website: DoDAF Architecture Framework – DoD Deputy Chief Information Officer
- Website: DoDAF Version 2.02 Journal