SysML 1.7 RTF Avatar
  1. OMG Issue

SYSML17 — Derived attribute should also be read only

  • Key: SYSML17-139
  • Status: closed  
  • Source: Commissariat a l Energie Atomique-CEA ( Mr. Benoit Maggi)
  • Summary:

    In the xmi file representing the profile, that can be found here:
    ptc/2015-07-05 http://www.omg.org/spec/SysML/20150709/SysML.xmi

    The derived attributes should also be set to read-only:
    <ownedAttribute xmi:id="SysML.package_packagedElement_Requirements.stereotype_packagedElement_Requirement_ownedAttribute.master" xmi:uuid="org.omg.sysml.SysML.package_packagedElement_Requirements.stereotype_packagedElement_Requirement_ownedAttribute.master" xmi:type="uml:Property">
    <name>master</name>
    <isDerived>true</isDerived>
    ...
    </ownedAttribute>

    In Papyrus SysML 1.1 version, the derived attributes have been set to read-only.
    It will be the same for SysML 1.4 implementation. See https://git.eclipse.org/r/#/c/71034/2/core/org.eclipse.papyrus.sysml14/resources/profile/SysML.profile.uml

    It would be good to provide for SysML 1.5 either the profile with readonly or specify in the norm what should be implemented for the write access

  • Reported: SysML 1.4 — Thu, 28 Apr 2016 10:42 GMT
  • Disposition: Closed; No Change — SysML 1.7
  • Disposition Summary:

    Proposal: Derived properties are not required to be read-only

    The UML specification allows that derived properties are changeable:

    ----------------------------
    Section 9.5.3:
    Derived Properties are often specified to be read-only (i.e., clients may not directly change values). But where a derived Property is changeable, an implementation is expected to make appropriate changes to the model in order for all the constraints to be met, in particular the derivation constraint for the derived Property. The derivation for a derived Property may be specified by a constraint.
    ----------------------------

    A derived property can change if a value of the derivation expression changes.

  • Updated: Thu, 22 Dec 2022 13:45 GMT