SysML 1.7 RTF Avatar
  1. OMG Issue

SYSML17 — 10.3.1.2 Parametric Diagram: square box notation

  • Key: SYSML17-17
  • Legacy Issue Number: 12131
  • Status: open  
  • Source: No Magic ( Darren Kelly)
  • Summary:

    10.3.1.2 Parametric Diagram: clarify applicability of square box notation to constraint parameters (or otherwise) SysML1.0, 10.3.1.2 Parametric Diagram: 'Small square box notation for an internal property A value property may optionally be shown by a small square box, with the name and other specifications appearing in a text string close to the square box. The text string for such a value property may include all the elements that could ordinarily be used to declare the property in a compartment of a block, including an optional default value. The box may optionally be shown with one edge flush with the boundary of a containing property. Placement of property boxes is purely for notational convenience, for example to enable simpler connection from the outside, and has no semantic significance. If a connector is drawn to a region where an internal property box is shown flush with the boundary of a containing property, the connector is always assumed to connect to the innermost property.' It is not clear whether 'value property' here is meant to refer to a constraint parameter. Also, the term 'internal property' does not exclude, for example, nested constraints, leaving open the possibility of drawing nested constraint properties using square box notation, which is surely not intended. The following suggests that only constraint parameters - not value properties - are intended: SysML1.0, , 10.3.2.1 ConstraintBlock: '[1] A constraint block may not own any structural or behavioral elements beyond the properties that define its constraint parameters, constraint properties that hold internal usages of constraint blocks, binding connectors between its internally nested constraint parameters, constraint expressions that define an interpretation for the constraint block, and general-purpose model management and crosscutting elements.' Rewrite SysML1.0, 10.3.1.2 Parametric Diagram, replacing all references to 'value property' and 'internal property' with 'constraint parameter': 'Small square box notation for a constraint parameter A constraint parameter may optionally be shown by a small square box, with the name and other specifications appearing in a text string close to the square box. The text string for such a constraint parameter may include all the elements that could ordinarily be used to declare the property in a compartment of a block, including an optional default value. The box may optionally be shown with one edge flush with the boundary of a containing property. Placement of constraint parameter boxes is purely for notational convenience, for example to enable simpler connection from the outside, and has no semantic significance. If a connector is drawn to a region where a constraint parameter box is shown flush with the boundary of a containing property, the connector is always assumed to connect to the constraint parameter.'

  • Reported: SysML 1.0 — Wed, 2 Jan 2008 05:00 GMT
  • Updated: Sat, 25 Apr 2020 00:08 GMT