Webel: MBSE: SysMLv1: Prefer a custom «actor» extension of a Block (such as the non-normative External) over UML-style Actor for use as parts in IBDs and on allocation swimlanes. You can also have a Trace from a block-based «actor» to a UML-style Actor.
Webel: SysML for MBSE: The frequent recommendation that each UseCase have at least one "primary" scenario is a very useful and highly recommended CONVENTION (only). But it is not actually enforced by the SysML1.7 or UML2.5.1 metamodels or specifications.
UML 2.5.1: «Trace»: As model changes can occur in both directions, the directionality of the dependency can often be ignored. The mapping specifies the relationship between the two, but it is rarely computable and is usually informal. Source Unified Modeling Language 2.5.1
UML 2.5.1: «Trace»: Specifies a trace relationship between model elements or sets of model elements that represent the same concept in different models. Traces are mainly used for tracking requirements and changes across models. Source Unified Modeling Language 2.5.1
Using a generic MagicDraw/Cameo query table to track /tracedTo for any NamedElement type using a derived relationship Gallery Tutorial TRAIL: Theory and best practices for the Webel Parsing Analysis recipe for SysMLv1.6+ Section Slide kind MagicDraw/Cameo: table table
The SysML1.6 derived /tracedTo is only available on AbstractRequirement (but in MagicDraw/Cameo you can use derived relationships to achieve the same thing on other kinds of NamedElement).
The SysML Trace relationship can be used as a quick way to traceably elicit model elements from an identified diagram or table from a domain source document. You may visually remove the Trace symbols as each element is elicited to reduce clutter.
The UML «Trace» and SysML Trace can't be applied to a Slot as target (because Slot is just an Element, not a NamedElement).
Using Trace to quickly elicit model elements from an identified figure, drawing, diagram, plot, graphic, or table from a domain source document Gallery Tutorial TRAIL: Theory and best practices for the Webel Parsing Analysis recipe for SysMLv1.6+ Section Slide kind SysML Block Definition Diagram (BDD)
Trace::getTracedFrom (in ref : NamedElement) : AbstractRequirement [0..*] 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 ... Source OMG Systems Modeling Language (SysML) 1.6
AbstractRequirement::/tracedTo : NamedElement [0..*] Derived from all elements that are the client of a «trace» relationship for which this requirement is a supplier. (derived) [ERROR] Source OMG Systems Modeling Language (SysML) 1.6
