Questions regarding Time Aware Modeling

[Viking]

Hi, I have following questions regarding Time Aware Modeling:

• Wouldn’t it be helpful also to support cloning of Relationships?
• Does UML support relationships between (different) relationships? I saw some diagrams, maybe hand-made or with some other tool. SparxEA does not support this, as far as I tried this. Otherwise, a trace between relationships would be very helpful from my point of view.
• Surprisingly I can draw a trace relationship from a relationship to itself in SparxEA. Is this intended?

[Eve]

Does UML support relationships between (different) relationships?

Not explicitly, but several of the relationships (eg. Dependency) have ends defined by types that include a number of relationships.

That doesn't necessarily mean that it's expected. LiteralNull is also a specialization of Element, so you could also have a dependency on a particular literal null. I don't think that's a reasonable interpretation of the intention of the specification.

Surprisingly I can draw a trace relationship from a relationship to itself in SparxEA. Is this intended?

I don't see a constraint on the specification that disallows it. You could argue that it's not expected by the authors of the spec, but I don't know how end users are using it. If you don't think it makes sense, don't use it.

[Viking]

Many thanks @Eve. Very helpful.

Could you also answer the other questions, please?

[Eve]

As I said in another thread you were part of...

I'm not going to discuss any feature requests here.

[Richard Freggi]

Does UML support relationships between (different) relationships?

Not explicitly, but several of the relationships (eg. Dependency) have ends defined by types that include a number of relationships.

That doesn't necessarily mean that it's expected. LiteralNull is also a specialization of Element, so you could also have a dependency on a particular literal null. I don't think that's a reasonable interpretation of the intention of the specification.

Surprisingly I can draw a trace relationship from a relationship to itself in SparxEA. Is this intended?

I don't see a constraint on the specification that disallows it. You could argue that it's not expected by the authors of the spec, but I don't know how end users are using it. If you don't think it makes sense, don't use it.

I vaguely remember that in UML a relationship is a class and as such it can have its own associations to other classes.  In EA I can draw an association between a class and an association (eg intersection entity in a ERD diagram).  Am I remembering it wrong?

[Eve]

I vaguely remember that in UML a relationship is a class and as such it can have its own associations to other classes.  In EA I can draw an association between a class and an association (eg intersection entity in a ERD diagram).  Am I remembering it wrong?

Close. In inherits from Classifier. As such, every relationship that can be from or to a classifier at least technically can reference an association. I don't think the specification explicitly uses them,

Like the metaclasses in my first answer, that doesn't necessarily mean that those relationships are expected. I would argue that it isn't expected because although it describes multiple Associations, some of which are logically specializing another one. In those situations it only defines a subsets between the ends instead of an explicit Generalization between the associations themselves.

EA still allows a Generalization between two Associations. It's allowed by the spec and it's useful in some circumstances. But that shouldn't be taken as justification that any other function EA provides for non-relationship elements should be extended to relationships.