SysMLv1.x: The ElementGroup stereotype

Gallery
Tutorial
TRAIL: Webel's ultimate guide to Systems Modeling Language (v1) with MagicDraw/Cameo
Section
18:01: Logical grouping with the ElementGroup extension of Comment in SysMLv1.x
Topic level
INTERMEDIATE
UML keywords
Comment
Comment::body
SysML keywords
ElementGroup
ElementGroup::/criterion
ElementGroup::/member
ElementGroup::/size
ElementGroup::name
ElementGroup::orderedMember
Slide kind
UML Profile Diagram
SysML-1.6: 'The ElementGroup stereotype provides a lightweight mechanism for grouping various and possibly heterogeneous model elements by extending the capability of comments to refer to multiple annotated elements. '
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The basic idea is that you can "logically" group members according to some text:
SysML-1.6: 'The criterion for membership in an element group is specified by the body of the comment the stereotype is applied to. By grouping elements, the modeler asserts that the criterion of the group applies to the member.'
And you can optionally order the members:
SysML-1.6: 'Optionally, members of an element group can be ordered using its orderedMember property.'
Note that:
SysML-1.6: 'Element groups do not own their elements and thus an element can participate in an unlimited number of groups.'
Therefore:
The grouping of member elements by an ElementGroup is denoted here "logical" in the sense that it does not "steal ownership" of member elements (as opposed to "physical" ownership of elements in the model)
There is an optional 'name' attribute:
SysML-1.6: 'Element groups are named using the name property.'
Webel Best Practice: Do not feel obliged to use the 'name' property of an ElementGroup if you don't feel it adds value.
Up next
SysMLv1.x: An ElementGroup used for basic Parsing Analysis model element elicitation: Example 1
Notes
[OPTION]{OPTION} Do not feel obliged to use the 'name' property of an ElementGroup if you don't feel it adds value.
[OPTION]{OPTION} The default display of all tagged values on the comment symbol for an ElementGroup can make diagrams cluttered, but you can extend it with a custom stereotype and customise the default visible tagged values.
[TIP]{INFORMATIVE} The grouping of member elements by an ElementGroup is denoted here "logical" in the sense that it does not "steal ownership" of member elements (as opposed to "physical" ownership of elements in the model)
Snippets (quotes/extracts)
  [SysML-1.6] The ElementGroup stereotype provides a lightweight mechanism for grouping various and possibly heterogeneous model elements by extending the capability of comments to refer to multiple annotated elements.
  [SysML-1.6] For example, it can group elements that are associated with a particular release of the model, have a certain risk level, or are associated with a legacy design.
  [SysML-1.6] The semantics of ElementGroup is modeler-defined. In particular, the body text is not restricted. It can describe the grouped elements as well as elements or values related to the grouped elements.
  [SysML-1.6] Element groups are named using the name property.
  [SysML-1.6] The criterion for membership in an element group is specified by the body of the comment the stereotype is applied to. By grouping elements, the modeler asserts that the criterion of the group applies to the member.
  [SysML-1.6] Optionally, members of an element group can be ordered using its orderedMember property.
  [SysML-1.6] ElementGroup::/criterion : String [0..1] Specifies the rationale for being member of the group. Adding an element to the group asserts that the criterion applies to this element. Derived from Comment::body. (derived)
  [SysML-1.6] ElementGroup::/member : Element [0..*] Set specifying the members of the group. Derived from Comment::annotatedElement. (derived)
  [SysML-1.6] ElementGroup::name : String [1] Name of the element group
  [SysML-1.6] ElementGroup::orderedMember : Element [0..*] Organize member according to an arbitrary order. Optional. (subsets: ElementGroup::member)
  [SysML-1.6] ElementGroup::/size : Integer [1] Number of members in the group. Derived. (derived)
  [SysML-1.6] Element groups do not own their elements and thus an element can participate in an unlimited number of groups.
Visit also
Visit also (backlinks)
TRAIL: Theory and best practices for the Webel Parsing Analysis recipe for SysMLv1.6+
Webel Parsing Analysis: The absolute basics of the process (SysMLv1.x form)
Webel Parsing Analysis for SysML: Requirements for the Parsing Analysis Container (a.k.a. Snippet)
SysMLv2: On the v2 Comment extension of the v2 AnnotatingElement as a candidate Parsing Analysis Container
SysMLv1.x: Q: Why can't a Package with PackageImports be used as a Parsing Analysis text container? Why is the SysML1.6 ElementGroup (extended and customised as the Webel «snippet») far better suited for text-driven model element elicitation?
TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model
TRAIL: Webel SysML Parsing Analysis example: A particle physics taxonomy from Wikipedia
The Webel Parsing Analysis recipe for SysML
Related slides (includes other tutorials)
Related slides (backlinks, includes other tutorials)
Containment tree view of members of a «snippet» ElementGroup in MagicDraw/Cameo
Simplified profile for Webel Parsing Analysis for SysML1.6+ in MagicDraw/Cameo (adapt as required)