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  1. OMG Issue

PSCS12 — Incorrect SysML term used in SysML Annex

  • Key: PSCS12-1
  • Status: closed  
  • Source: NIST ( Conrad Bock)
  • Summary:

    The term "behavior proxyport" isn't in SysML, but is used in Annex B many times. Ports can't be both behavioral and proxy. Informally, both kinds of port "stand in" for other objects, but behavior ports stand in for the owning object, while proxy ports stand in for internal parts. I think the Annex is referring to behavior ports, at least I recall Clause 11.2.2.3 (Block with Multiple Behavior ProxyPorts) is. The error seems to be causing some of the SysMLers to think the annex applies to proxy ports.

  • Reported: PSCS 1.0 — Thu, 22 Sep 2016 13:37 GMT
  • Disposition: Closed; No Change — PSCS 1.2
  • Disposition Summary:

    Annex B is correct

    Annex B does in fact apply specifically to ProxyPorts, and only to ProxyPorts. And it also only applies to ProxyPorts with isBehavior = true, that is, "behavior" ProxyPorts. Note that, in UML, a behavior Port does not actually have its own behavior, but has its behavior handled by the classifier behavior of its owning object, rather than via a delegation connector. (See the definition of Port::isBehavior and the corresponding semantics specification in subclause 9.3.12 of the UML 2.4.1 specification or subclause 11.3.3.1 of the UML 2.5.1 specification.)

    Further, SysML does in fact allow behavior ProxyPorts. According to he SysML 1.4 specification (on which the Annex is based), subclause 9.3.2.12 (emphasis added),

    Completely specified proxy ports must be connected to internal parts or be behavioral, to enable the owning block or connected internal parts to handle or initiate any interactions through the port.

    "Being behaviorial" is interpreted here as meaning isBehavior = true. This is as opposed to FullPorts, which "cannot be behavioral (isBehavior = false)" according to constraint [3] of subclause 9.3.2.8 of the SysML 1.4 specification.

    There for, the Annex is essentially correct in discussing "behavior ProxyPorts". The SysML 1.4 specification actually uses the term "behavioral port", but the more proper term according the UML specification is really "behavior port".

  • Updated: Tue, 18 Dec 2018 21:02 GMT