By Ron Kratzke, Principal Systems Engineer
The following conversation is a question and response on the Vitech Community Site Forums– feel free to comment on the forums or join the Vitech LinkedIn page with your questions!
For the “Performs/Allocated To” relation between Components and Functions or Performers and Operational Activity the Behavior Types are:
a. Atomic
b. Capability
c. Integrated (Root)
d. Integrated (Services)
e. Thread
There is a brief discussion in the System Definition Guide, but it only mentions Atomic and Integrated (Root). I have failed to find any documentation on the other 3 choices.
My questions are:
1. Where are these selections documented?
2. What are the implications of the different settings, specifically on the SDD (System Description Document) and the SV-4?
Response:
There is not a specific section in the Systems Definition Guide or the Systems Architecture Guide which details the five relationship attributes listed above.
Behavior attributes are intended to provide additional information concerning the relationship of an element to the overall system design. There does not exist a prescribed use of this feature which must be followed to discontinuities. Rather they are provided as a feature to allow discrimination of functional models and thereby support enhanced organization and understanding of the system model.
When working on a system design effort using the basic schema the relation attributes are limited to Atomic, Integrated (Root), and Thread. As discussed in the SDG, these attributes are provided to indicate how the function is related to the architecture. The SDG specifically states that the attribute “Integrated (Root)” is utilized to indicate a top level function, one which will have decomposition below this functions. The attribute “Atomic” is then utilized for functions which form the decomposition of the “Integrated (Root)” function.
The “Thread” relation attribute is provide so that one can indicate a threads and distinguish these sets of functions from functions which are used in the integrated system behavior.
When working on a project using the extended schema (the DODAF Schema) and completing Operational Architectures, the available relation attribute list is extended by adding “Capability” and “Integrated (Services).” These two choices are provided to support Operational Activity modeling efforts and to provide the user the ability to distinguish between Operational Activities that support basic capabilities and Operational Activities supporting a service-oriented architecture.
The SDD script uses relations to provide elements for the various sections. When a component is selected for the subject of the SDD, the script looks at that component and the component’s relations to develop the document. For generation of Section 8 – Functional Behavior Model, the script reports on the functions which the selected component “performs.” Normally, this is just the “_Performs Component Name Functions.” It does not select only those functions with the relation attribute set to “Integrated (Root).” If the use makes the relation from the component to one or more Threads used in development of the system, the Thread will be reported on in this section.
The SV-4 (Systems Functionality Description) is more discriminating. This view point restricts the output of the selected Architecture “composed of” Components (Type=System) using the “performs” Function (Behavior Type = Integrated (Root)). The specifics selection logic for DoDAF Architecture views is provided in the help file associated with the script.
