GPCA — Viewpoints¶

In ISO/IEC/IEEE 42010 a viewpoint is the set of conventions for constructing and interpreting a view: whose concerns it frames, what it may contain, and how it is read. A view without a viewpoint is a picture; a view with one is a claim that can be checked.

MEMO makes viewpoints first-class. Each is a Viewpoint part carrying audience, concernKinds, stage, and the model layers it may draw from. GPCA's diagram views name ten of them.

The ten viewpoints in use¶

Viewpoint	Purpose	Audience	Concerns framed	Stage
`ContextViewpoint`	Communicate operational context and boundaries	System architect	Safety, Interoperability	Context
`OperationalViewpoint`	How actors interact and which capabilities they invoke	Project lead, System architect	Performance, Interoperability	Context
`FunctionalViewpoint`	Functional decomposition and behaviour	System architect	Safety, Performance	Architecture
`LogicalArchitectureViewpoint`	Logical decomposition	System architect	Safety, Performance	Architecture
`SoftwareViewpoint`	Software architecture for IEC 62304	Software architect	Safety, Reliability	Architecture
`PhysicalViewpoint`	Physical realization and interconnections	Hardware engineer	Reliability, Interoperability	Architecture
`RequirementsViewpoint`	Requirements decomposition and traceability	Regulatory engineer, System architect	Regulatory, Safety	Requirements
`RiskViewpoint`	Safety risk chains and controls	Safety engineer	Safety, Regulatory	Risk
`CybersecurityViewpoint`	Cybersecurity design, threats, cyber risk posture	Security engineer	Cybersecurity, Privacy, Safety	Risk
`VerificationViewpoint`	V&V coverage against requirements	Verification engineer	Safety, Regulatory	Verification

Viewpoints defined but not used by GPCA diagrams¶

The ontology also defines UsabilityViewpoint (usability engineer, safety engineer — usability and safety concerns) and ClinicalViewpoint (clinical engineer, regulatory engineer — safety and clinical concerns). GPCA holds the underlying content — use errors, foreseeable misuse, intended use, use context — but no diagram view currently names either viewpoint. That content reaches reviewers through the document views instead.

This is worth stating plainly rather than hiding: it is a gap in the diagram-level conformance chain, not a claim of completeness.

Default view kind¶

A cataloged viewpoint also declares the SysML v2 view kind it resolves to by default, so a reviewer knows what shape of diagram to expect before opening one. From memo_viewpoints_catalog:

Viewpoint concern area	Default view kind
Model content	`browser`
System context, use cases	`general`
Clinical workflow, operative scenario, functional flow	`actionflow`
Functional / logical architecture, decomposition	`general`

The resolution is a default, not a constraint — LogicalArchitectureViewpoint governs five GPCA views across four different view kinds, because "logical architecture" is legitimately asked about in several shapes.

Reading a viewpoint declaration¶

part logicalArchitectureViewpoint : Viewpoint {
    attribute :>> name = "LogicalArchitectureViewpoint";
    attribute :>> purpose = "Describe the system's logical decomposition.";
    attribute :>> audience = (AudienceKind::systemArchitect);
    attribute :>> stage = WorkflowStageKind::architecture;
    attribute :>> concernKinds = (ConcernKind::safety, ConcernKind::performance);
}

Every claim in the table above is read from declarations like this one, so the documentation cannot drift from the model without the model changing first.

Continue to Views.