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  1. OMG Issue

SYSML11 — Section: 8/3

  • Key: SYSML11-63
  • Legacy Issue Number: 11622
  • Status: closed  
  • Source: THALES ( Sebastien Demathieu)
  • Summary:

    Mapping of PropertySpecificType to the UML metamodel requires further explanation Chapter 8 introduces the notion of property-specific type to assign values to parts inside an ibd. Section defines a notation for property-specific types. Section provides a definition of the <<propertySpecificType>> stereotype and gives elements on how this concept maps to the UML metamodel. However, this section does not explicitly define: 1) where are stored the actual values? One may understand that a default value of a property owned by a class, which is stereotyped as <<propertySpecificType>>, is considered as a property-specific value. This property-specific value may be considered as an instance of a property owned by the refrenced block. It is not clearly stated though. 2) how does a property-specific type relate to the referenced block ? In other words, if a class is stereotyped as <<propertySpecificType>>, which feature of this class points to the referenced block? We may need to add a paragraph in section that provides answers to questions.

  • Reported: SysML 1.0 — Thu, 18 Oct 2007 04:00 GMT
  • Disposition: Resolved — SysML 1.1
  • Disposition Summary:

    A property-specific type defines a new specialization of a single existing classifier, which was used to type a single property in the definition of a block which owns that property. The PropertySpecificType stereotype is used in the SysML metamodel to distinguish a classifier created by this mechanism from classifiers created by all other forms of user definitions.
    Within the property-specific type, new or redefined properties or other features such as operations may be defined. Within a property defined within a property-specific type, one option is to specify a default value. As the resolutions for issues 10473 and 11502 indicate, however, an initialValues compartment may be used instead of a property-specific type if all that is needed are context-specific values and not a more customized definition of the classifier that types a property.
    If the property-specific type is used to define a feature that carries its own default value, that default value is specific to that property. The default value of a property owned by a classifier carries its value by means of a UML ValueSpecification. It is not considered as an instance of the property, and the classifier provides only the definitions of its properties and not any instance to be referenced.
    The suggestion to add a paragraph to Section to better explain the PropertySpecificType stereotype is valid, and Issue 11308 also requested somewhat less obscure explanation of the meaning of this stereotype. A full explanation of the representation of the metamodel representation of a property-specific type would benefit from examples of metaclass instances that could be represent specific example models, but the SysML specification does not currently include such metamodel instance examples. The revised text below is intended as an initial start toward a somewhat less opaque explanation, but falls short of full metamodel examples or other forms of explanations which could still be considered for future revisions of the spec.

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