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  1. OMG Issue

UML24 — Parameter semantics related to Behavior and BehavioralFeature

  • Key: UML24-119
  • Legacy Issue Number: 15787
  • Status: closed  
  • Source: Model Driven Solutions ( Steve Cook)
  • Summary:

    On my first UML 2.5 efforts at consolidating the semantics of Classifiers in the merged model it becomes very obvious that Parameter has two sets of semantics: one related to the parameters of BehavioralFeatures and one related to the parameters of Behaviors.

    ParameterSet semantics talks almost exclusively about Behaviors. There is a forward reference in 12.3.13 that says “See semantics of ParameterSet”. But all 12.3.43 says is “A behavior with output parameter sets can only post outputs to the parameters in one of the sets per execution. The same is true for operations with parameter sets.” 12.3.13 also says “See notation for ParameterSet” – that is simply false, because 12.3.43 only has notation for Behaviors (well, actually Activities, because Behavior has no notation (13.3.2) but that’s the topic of a separate discussion).

    ParameterEffectKind, as well, talks exclusively about Behaviors.

    So on the face of it, the Parameter behavior related to BehavioralFeatures is distinct from the Parameter behavior related to Behaviors.

    Now, in the UML specification, there actually appear to be two separate metaclasses called Parameter. There is the one defined in Kernel, together with the one defined in Collaborations as a merge increment: the merge happens via Collaborations->InternalStructures->Interfaces->Dependencies->Kernel.

    There is a second one defined in CompleteActivities. According to the specification text, this is a specialization (it does not say merge) of the one in Kernel. However these are the merges: CompleteActivities->IntermediateActivities->BasicActivities->FundemantalActivities->BasicBehaviors->Kernel. So CompleteActivities::Parameter is also merged with the others.

    The end result is Parameter which defines both direction: ParameterDirectionKind and effect: ParameterEffectKind, that can be organized into subsets, regardless of where it is used. But there are almost no semantics and no notation specified for the Behavior-oriented features as they relate to BehavioralFeature.

    One explanation of this might that the merge is accidental, and there are supposed to be two definitions of Parameter. This is belied, however, by 12.3.13 and figure 12.18.

    Can anybody explain what this is supposed to be about? Are these meanings of Parameter really supposed to be integrated like this? What are the meanings of effect and parameterSet for Operations and Receptions? What is the relationship between direction and effect for a Parameter?

  • Reported: UML 2.3 — Wed, 27 Oct 2010 04:00 GMT
  • Disposition: Resolved — UML 2.4
  • Disposition Summary:

    In UML 2.5 it has been made clear that there is only one metaclass Parameter and its semantics are now defined in one
    Disposition: Closed - No Change

  • Updated: Fri, 6 Mar 2015 20:58 GMT