F3_SPRO System Process Viewpoint

Domain	Aspect	Maturity
Functional	Process & Behavior	released

Purpose

The System Process Viewpoint provides the functional representation of the system using a black-box approach

• the representation of the SOI and all Context Elements
• the System Functions the SOI shall be able to perform
• the Context Functions the Context Elements are expected to perform
• the exchange between SOI System Functions and Context Functions of Context Elements
• the functional flows crossing the boundary between SOI and Context Elements

Applicability

The System Process Viewpoint supports the “prepare for system requirement definition” activity included in the “System Requirements Definition Process” activities of the INCOSE SYSTEMS ENGINEERING HANDBOOK 2023 [§2.3.5.3] and contributes to the functional boundary definition, and the System Interface definition.

Supported Processes

• System Requirements Definition ProcessISO 15288:2023[6.4.3]

Supported Information Items

• System function identificationSEHB V4[Appendix E]
• System function definitonSEHB V4[Appendix E]
• System interface definition SEHB V5[Appendix E]
• System Viewpoints, views and modelsSEHB V5[Appendix E]
• System architecture descriptionSEHB V5[Appendix E]

Presentation

An activity diagram featuring the ordered execution of System Process Actions. The activity diagram swim lanes are typed with Context Element usage and SOI usage from the same System Context. Note: In order to improve the clarity of presentation it may be appropriate to use several activity diagrams for one System Process.

A tabular format listing all identified System Functions, the System Processes in which they appear, and the Comtext Exchange with the Context Functions.

Stakeholder

• Acquirer
• Customer
• Hardware Developer
• IV&V Engineer
• Operator
• Project Manager
• Safety Expert
• Security Expert
• Software Developer
• Supplier
• System Architect
• User

Concern

• How does a system function interact with its environment?
• How is the system interacting with the identified external entities?
• What are necessary inputs for operating the system expected to be provided by other external entitys?
• What are the scenarios a system function is utilized in?
• What is the functional scope of the system?
• What services are expected from external entities?
• Which are the conceptual interfaces of the system?
• Which functions are out of scope of the system?
• Which functions will the system provide?

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.
General Function Usage Exchange Point	A parameter of a System or Context Function.
Logical Context Element Role	Specifies the fact that a Logical Context Element exists in a given Logical System Context.
General Functional Exchange	Specifies the fact that an General Functional Exchange between General Function Parameters is taking place.
Logical SOI Role	Specifies the fact that a Logical Context SOI exists in a given Logical System Context.
Context Function IN System Process	Specifies the fact that a Context Function is used in a System Process.
System Process	Specifies the fact that a System Process captures system behavior as a specific sequence of actions or tasks, and system exchanges including information, materials, energy, etc.
Context Function	Specifies the fact that a fundamental action or task is expected to be carried out by an External Entity. Note: The intention is to capture the expectations and to explicitly dissect the functionality. This must not be interpreted as an attempt for a behavior specification of an External Entity. Capturing this valuable information is the basis to reach agreement on the functionality at the System boundary by clarifying the expectations about what is performed by Context Elements.
LCEperformingCFN	Specifies the fact that a Context Function is expected to be carried out by the Logical Context Element in this System Context.
LETperformingSFN	Specifies the fact that a System Function is expected to be carried out by the SOI in this System Context.
GFNcontrolledAFTER	Specifies a sequential execution of Functions.
System Function IN System Process	Specifies the fact that a System Function is used in a System Process.

Realization of exposed Concepts

The Diagram shows the realization of exposed concepts.

The Table shows the realization of exposed concepts.

Concept	Realization
System Function	SAF_SystemFunction
General Function Usage Exchange Point	Parameter
Logical Context Element Role	SAF_LogicalContextRole
General Functional Exchange	ObjectFlow
Logical SOI Role	SAF_LogicalContextRole
Context Function IN System Process	SAF_ContextAction contained in SAF_SystemProcess
System Process	SAF_SystemProcess
Context Function	SAF_ContextFunction
LCEperformingCFN	Allocate
LETperformingSFN	Allocate
GFNcontrolledAFTER	ControlFlow
System Function IN System Process	SAF_FunctionAction contained in SAF_SystemProcess

Related Viewpoints

Required Viewpoints

Recommended Viewpoints

• Operational Context Definition Viewpoint

Example