SYSML17 — Representation of nested object nodes in activity diagrams

Issue: Representation of nested object nodes in activity diagrams. Discussion: It is desirable to be able to represnt nesting of object nodes on activity diagrams to reflect one or more levels of nested properties of the classifier that types the object node. For example, if water is shown as an object node, and it is desired to refer to the temperature of water, then it should be possible to reflect this property on the activity diagram using the notations that are used on ibd's. In particular, one may want to use either a nested rectangle to represent the property, or the dot notation. Proposed update. In the diagram extensions for activity diagrams in Section 11.3.1.4, add a clarifying statement that nested properties of the classifier that types an object node can be represented on activity diagrams either using the nested rectangle notation or the dot notation similar to the use of nesting on ibd's and parametric diagrams.

Corresponding actions shall be used

• There are two possible cases we see where we would need to work on parts from a whole: (a) the part remains owned by the whole and we just need a reference on it to focus the folowwing behavior on this part, or (b): the part is "dismounted" from the whole (i.e. the ownership changes) and then tit is flowing apart from the whole. In both cases it's necessary to specifiy the appropriate action to be performed:

• in case (a): actions like "UnmarshallAction" or "ReadStructuralFeatureAction" can be used. Alternatively the "transformation" property of an ObjectFlow can be used. Note that this transformation shall be "side effect free".

• in case (b): we would use "RemoveStructralFeatureValueAction" for transferring ownership

We propose a "Closed, no change" resolution.