SYSML16 — Update to Trace Relationship’

I potentially found a mistake in the latest SysML specification. It can be found on page 144. The “Trace Dependency” and the “TraceCallout” are introduced on this page. Usually these two visualizations should show the same aspect of a SysML model. Unfortunately the “Trace Dependency” is only introduced between two requirements whilst the “TraceCallout” is shown between a requirement and a more general NamedElement. I think the named element should be allowed in both cases in the client role of the trace dependency. ADDITIONAL TEXT

The trace stereotype as defined in 16.3.2.7 does not constrain either end of the trace relationship than the having one client and one supplier.

16.3.2.7 Trace
Description
The Trace stereotype specializes UML4SysML Trace and DirectedRelationshipPropertyPath to enable traces to identify their sources and targets by a multi-level path of accessible properties from context blocks for the sources and targets.
Constraints
[1] The Trace stereotype may only be applied to dependencies.
[2] Dependencies with a Trace stereotype or one of its specializations applied must have exactly one client and one supplier.

From the UML 2.5 Standard Profile, the UML4SysML::Trace extends Abstraction, which subclasses Dependency. Dependencys are directed relationships between Named Elements. Therefore, the SysML::Trace can have any Named Element as its ends.

The diagram elements Table 16.2 on pg 144 should be clarified.

Also, in section 16.3.2.7, the trace relationship has specific definitions for Requirements:

Operations
[1] The query getTracedFrom() gives all the requirements that are clients (from end of the concrete syntax) of a Trace
relationship whose supplier is the element in parameter. This is a static query.
Trace::getTracedFrom(ref : NamedElement) : Set(Requirement )

getTracedFrom=Requirement.AllInstances()>select(traceTo>includes(ref))

The query getTracedFrom() could be more general and query all NamedElements and not only Requirements.

Defer

Postponed to the next RTF