Here is the outcome I am looking for:
- Visually show a composition or aggregation as elements embedded within another element, bonus if that creates a relationship between the elements
- Ability to expand and collapse that view, in the same way as UML composite elements can expand and collapse in EA
- Have this captured in the model *not* just the diagram so that if I add the composite element to a different diagram I can also expand or contract with the same composed elements
Ok, so here is where I got to ...
Option 1: use the standard EA auto-grouping behavior.
- Works with archimate shapes and shows the visual grouping I am after
- Sometimes nests elements sometimes doesn't (depends on type and package)
- Doesn't create a relationship automatically, but does auto-hide composition and aggregation relationships if they have been defined (nice)
*but*
- Doesn't support collapse / expand of the group
- Only does this per diagram, if I drop the same 'parent' element on another diagram there is no indication that there are sub-elements, the sub-elements need to be dropped and laid out again
Option 2: use a composite structure diagram
- Shows the internal sub-element structure with the visual grouping
- Is captured in the model so works across multiple diagrams and supports collapse / expand
*but*
- Doesn't work with archimate shapes as the parent, need to use a standard UML shape
- Is a bit more stuffing around
Neither is quite what I'm after, but either can be good enough, I'm using both variants as appropriate.
Now just need to work on getting derived relationships ... (no - I'm not holding out for this one anytime soon)
