SysMLv1.x: An ElementGroup in the model tree browser of MagicDraw/Cameo

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
SysML keywords
ElementGroup
ElementGroup::/criterion
ElementGroup::/member
ElementGroup::/size
ElementGroup::name
Keywords
Slide kind
MagicDraw/Cameo: table
SysML Block Definition Diagram (BDD)
This topic is now also covered in more detail in a separate dedicated tutorial trail:
NEWS: New detailed tutorial: TRAIL: Theory and best practices for the Webel Parsing Analysis recipe for SysMLv1.6+
This slide shows an ElementGroup in the model tree browser of the MagicDraw SysML Plugin or Magic Cyber-Systems Engineer ® (Cameo Systems Modeler®):
Click on the image to view it full size
All of the elements appear "under" the named ElementGroup node in the model tree browser, but they are of course NOT in any sense owned by that ElementGroup:
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)
It's a nice tool feature, however:
MagicDraw/Cameo: The apparent grouping of member elements under an ElementGroup node in the model tree can cause complications for searching and for the Cameo Collaborator exports.
We'll look quickly next at how one can extend the ElementGroup with a custom Sterotype and customise it in the tool.
Up next
SysMLv1.x: Extending the ElementGroup for the Webel Parsing Analysis recipe (a quick look)
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 Webel Parsing Analysis recipe for SysML1.x does not use the ElementGroup directly, it extends it as a user-defined Snippet stereotype with keyword «snippet» and with MagicDraw Customization.
[TOOL]{INFORMATIVE} In MagicDraw/Cameo the dashed line symbol from a UML Comment or SysMLv1.x ElementGroup to an annotatedElement is called an 'anchor'.
[TIP]{INFORMATIVE} An ElementGroup comment symbol may appear on more than one diagram type and may collect different kinds of anchored annotatedElement members from more than diagram.
[ISSUE, TOOL] MagicDraw/Cameo: The apparent grouping of member elements under an ElementGroup node in the model tree can cause complications for searching and for the Cameo Collaborator exports.
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)
  [UML-2.5.1] A Comment is shown as a rectangle with the upper right corner bent (this is also known as a “note symbol”). The rectangle contains the body of the Comment. The connection to each annotatedElement is shown by a separate dashed line.
Visit also
Visit also (backlinks)
TRAIL: Theory and best practices for the Webel Parsing Analysis recipe for SysMLv1.6+
Webel Parsing Analysis for SysML: Requirements for the Parsing Analysis Container (a.k.a. Snippet)
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)