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  1. OMG Issue

SYSML17 — Suggest introduce strict diagram policy: avoid "elided Pin" ObjectNode notation in Activity Diagrams in all revised and future specification figures

  • Key: SYSML17-357
  • Status: open  
  • Source: Webel IT Australia ( Dr. Darren Kelly)
  • Summary:

    I suggest that diagram submitters never ever again use the infamous "elided Pin notation" for ObjectNode anywhere in the spec, as it is widely misunderstood and the tool support for it is poor (broken).

    This concerns not only the Annex D sample problem, but all other Activity Diagrams in all figures in the spec.

    The problematic "elided Pin" notation as described in UML-2.5.1 :

    'An object flow is notated by an arrowed line. In Figure 15.9, upper right, the two object flow arrows denote a single object flow edge between two pins in the underlying model, as shown in the lower middle of the figure.'

    The relevant UML-2.5.1 Figure 15.9 ObjectFlow notations is attached.

    Please note how it describes the notation as two object flow arrows (notational symbols that do not correspond one-to-one to ActivityEdge elements, but rather to one ObjectFlow edge). Note also how it says there are two Pins in the underlying model.

    At least one tool implements this notation incorrectly and uses 2 ObjectFlows and a CentralBufferNode instead of two arrows and a rectangular symbol representing any ObjectNode sub-type.

    I appreciate the OMG JIRA is not intended for personal remarks, but I can't begin to explain how much time wrangling with broken "elided Pin" ObjectNode notation in one tool has cost me, time which could be better used contributing to the specification. I ask you all to please vote yes for this in a ballot soon so that I can contribute more.


  • Reported: SysML 1.6 — Wed, 1 Jul 2020 11:31 GMT
  • Updated: Wed, 21 Apr 2021 03:47 GMT
  • Attachments: