Coregions in UML

Question

What are coregions in UML sequence diagrams?

score 3 · Accepted Answer · answered Jan 22 '10 at 01:08

3

Coregions are used when the sequence of events does not matter, that is they can occur safely in any order.

This is one of the first few pages I found when I searched coregion sequence diagram in Google.

answered Jan 22 '10 at 01:08

Vincent Ramdhanie

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I found that link too, but I wasn't certain if it is relevant, because it is targeted at MSC, not UML. However it helped, thank you. – Gabriel Ščerbák Jan 22 '10 at 01:42

score 2 · Answer 2 · answered Jan 24 '10 at 18:38

The coregion is a notational/sytanx choice for representing parallel CombinedFragments the UML 2.2 Superstructure spec (14.3.3) says:

Parallel The interactionOperator par designates that the CombinedFragment represents a parallel merge between the behaviors of the operands. The OccurrenceSpecifications of the different operands can be interleaved in any way as long as the ordering imposed by each operand as such is preserved. A parallel merge defines a set of traces that describes all the ways that OccurrenceSpecifications of the operands may be interleaved without obstructing the order of the OccurrenceSpecifications within the operand.

The answer above is correct this is just more context.

score 1 · Answer 3 · answered Aug 02 '12 at 10:24

The UML is specified by the OMG in the two documents (http://www.omg.org/spec/uml): The UML Infrastructure and the UML Supestructure. Whatever documentation may be not official.

In the UML superstructure section 14.3.3 it is said:

A notational shorthand for parallel combined fragments are available for the common situation where the order of event occurrences (or other nested fragments) on one Lifeline is insignificant. This means that in a given “coregion” area of a Lifeline all the directly contained fragments are considered separate operands of a parallel combined fragment.

Coregions in UML

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