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  1. OMG Issue

SYSML11 — Section: 6.1 Levels of Formalism

  • Key: SYSML11-24
  • Legacy Issue Number: 10472
  • Status: closed  
  • Source: Deere & Company ( Roger Burkhart)
  • Summary:

    Add a brief statement to Section 6.1, Levels of Formalism, to clarify that SysML reuses UML instance semantics, adapted as necessary for description of systems. A brief statement of UML instance semantics can be found in the UML Superstructure specification (ptc/06-04-02) under 6.4.2, Semantic Levels and Naming, under the paragraph labeled "Instance level."

  • Reported: SysML 1.0b1 — Mon, 27 Nov 2006 05:00 GMT
  • Disposition: Resolved — SysML 1.1
  • Disposition Summary:

    Following is the paragraph labed "Instance level," which now appears in the
    section numbered 6.3.2 in the UML 2.4 Superstructure Specification:
    Instance level – These are the things that models represent at runtime.
    They don’t appear in models directly (except very occasionally as detailed
    examples), but they are necessary to explain the semantics of what
    models mean. These classes do not appear at all in the UML2 metamodel
    or in UML models, but they underlie the meaning of models. We provide a
    brief runtime metamodel in the Common Behavior chapter, but we do not
    formally define the semantics of UML using the runtime metamodel. Such
    a formal definition would be a major amount of work.
    Since SysML already includes the semantics of existing UML elements, except
    as specifically changed or extended by SysML, this existing language (which has
    not changed since UML 2.1) applies to SysML.
    SysML already includes the following statement in Section 6.1, which leaves
    open the option to consider further semantics in the future, but in the meantime
    leaves them open just as does UML:
    SysML is specified using a combination of UML modeling techniques and
    precise natural language to balance rigor andunderstandability. Use of
    more formal constraints and semantics may be applied in future versions
    to further increase the precision of the language.
    Given the generality of both the UML and SysML statements about formal
    semantics, no change is required to the current version of the SysML
    specification. A new issue could be raised if future versions of UML adopt a
    formal specification of semantics that would also need to be adapted or reflected
    by SysML, but such an issue should be raised against specific future changes to
    UML.
    Disposition: Closed, no change

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