SysML 1.1 RTF Avatar
  1. OMG Issue

SYSML11 — Section: 8.3.1.2 Internal Block Diagram Extensions

  • Key: SYSML11-77
  • Legacy Issue Number: 11819
  • Status: closed  
  • Source: oose Innovative Informatik eG ( Tim Weilkiens)
  • Summary:

    Please provide a notation variant that allows to show block stereotypes at property elements typed by those blocks in an ibd. Similar to the notation variant that CallBehaviorActions can show the stereotypes of the called Behavior element. For example a common approach is to define stereotypes for discipline specific elements like <<hardware>>, <<software>>, <<mechanic>>, and so on. It is important to see the information in a bdd and ibd. It is circumstantial and superfluous to define two stereotypes for blocks and properties.

  • Reported: SysML 1.0 — Fri, 14 Dec 2007 05:00 GMT
  • Disposition: Resolved — SysML 1.1
  • Disposition Summary:

    The internal block diagram already allows any compartment of a block or value type that types a property to be shown within the property box on the diagram. Section 8.3.1.2 Internal Block Diagram, subsection "Compartments on internal properties" specifies, "SysML permits any property shown on an internal block diagram to also show compartments within the property box. These compartments may be given standard or user-customized labels just as on block definitions."
    A valid use of this option is to show a stereotype compartment, with or without any stereotype properties, as one of the compartments on the property box. This provides an existing graphical option to display the stereotype for a block or value type that types a property on an ibd.
    While the specifications places no restrictions on the compartments from the property type that may be shown on the property, in practice this could lead to confusion or ambiguity as to whether a compartment shown belongs to the property or to the type. The potential for such ambiguity is even higher if the property were to specify a property-specific type, since then the compartment could be used to define or redefine new features specific to the definition of the property itself.
    To remove any ambiguity for a compartment shown on a property, a graphical convention can be established to clearly mark and indicate a compartment whose contents are entirely the contents of the type of the property.
    Such a convention takes advantage of the customizability of compartment labels, and their definition as purely notational options on diagrams which are not defined formally anywhere in the SysML metamodel, is to use a special form of compartment label for these "type-derived" labels.
    For consistency with other aspects of ibd syntax, in which a ":" character separates a property name from its type, or which can precede the type when no property is shown, the recommended convention is to precede the "type-derived" compartments shown on an ibd with a colon.
    The revised text below establishes the colon prefix convention on a compartment label for any compartment which only displays contents of its type.
    Issue 11496, "It is not allowed in UML to display stereotypes of related elements," also noted the use of "secondary references" on both activities and blocks, including allocations on parts. Chapter 11 Activities already provides specific diagram extensions to display stereotypes of a defining element on a CallBehaviorAction, ObjectNode, or parameter. The colon prefix can also be used on an "allocatedFrom" or "allocatedTo" compartment label, as defined in Chapter 15 Allocations, to distinguish an allocation already established on the type of property from the property itself. At least some of the cases itemized by Issue 11496 are covered either by the explicit diagram extensions on activities or the use of compartments from a property type on an ibd.

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