F3_SFRE System Functional Refinement Viewpoint
| Domain | Aspect | Maturity |
|---|---|---|
| Functional | Process & Behavior |  under construction |
Purpose
The System Functional Refinement Viewpoint analyses decomposition of System Functions into System Partial Functions in order achieve understanding and agreement about the System functions sufficient to derive system requirements.
Applicability
The System Functional Refinement Viewpoint supports the activities included in the “System Requirements Definition Process” of the INCOSE SYSTEMS ENGINEERING HANDBOOK 2023 [§2.3.5.3]. The System Functional Refinement Viewpoint contributes to the System Function definition.
Supported Processes
Supported Information Items
Presentation
Activity Diagram featuring System Partial Functions, functional exchange between partial functions. There are explicitely no Swimlanes and no allocations to structure.
Stakeholder
Concern
- How are the system functions decomposed into smaller, and more manageable sub-functions?
- What are the interactions and dependencies between the different identified sub-functions?
- What is the breakdown of functions into sub-functions?
Exposed Concepts
The Diagram shows the concepts exposed by the viewpoint, and related concepts if necessary.
The Table shows the concepts exposed by the viewpoint, and related concepts if necessary.
| Concept | Documentation |
|---|---|
| System Function | Specifies the fundamental action or task that have to take place in the System in accepting and processing the inputs and in processing and generating the outputs. A System Function * accepts input from the System boundary * exposes its output at the System boundary * changes the System's State * is dependent on System's State Note: A System Function does not need to expose observable output, when it changes the System's state in a way that is observable by other system functions. Furthermore, a System Function does not need to accept any input from the system boundary, when it is dependent on the System State, which in turn is changeable by other System Functions. |
| System Partial Function in System Function | Specifies that a System Partial Function is used in a system function |
| GFNcontrolledAFTER | Specifies a sequential execution of Functions. |
| General Function Usage Exchange Point | A parameter of a System or Context Function. |
| General Functional Exchange | Specifies the fact that an General Functional Exchange between General Function Parameters is taking place. |
| GFEbeingPartOfGFNU | Specifies the fact that a Functional Exchange appears within a general Functiona Usage. |
Realization of exposed Concepts
The Diagram shows the realization of exposed concepts.
The Table shows the realization of exposed concepts.
Related Viewpoints
Required Viewpoints
Recommended Viewpoints
Example
