UML 1.4 MAILINGLIST Avatar
  1. OMG Issue

UML14 — Aggregation is poorly defined

  • Key: UML14-858
  • Legacy Issue Number: 1389
  • Status: closed  
  • Source: Anonymous
  • Summary:

    Summary: 1. Aggregation is poorly defined. It is not clear whether it is meant to be
    configurational and/or invariant (reading different parts of the documents
    give different signals). Instead it concentrates on lifetime dependency
    and unique connections. I believe it is intended to be invariant but not
    necessarily configurational. Firstly, that definition needs tightening and,
    to me and Jim Odell, being configurational seems to be a prime requirement
    for aggregation. Without it we really have a membership (yet still whole-part)
    relationship.
    Secondly, whatever the definition decided upon, its use in the metamodel must
    be clear and clean. At present, I believe many of the "black diamonds" in the
    metamodel really are not strong aggregations (whichever definition I try
    to use).

  • Reported: UML 1.1 — Tue, 19 May 1998 04:00 GMT
  • Disposition: Resolved — UML 1.2
  • Disposition Summary:

    Considered and declined.

  • Updated: Fri, 6 Mar 2015 21:35 GMT