Re: Association navigability issue.

Re: Association navigability issue.

From: Vladimir Mencl <>
Date: Sun, 26 Nov 2006 22:24:09 +1300
Message-ID: <>
On 11/25/2006 08:26 AM, Milan Milanovic wrote:
> Hi all,
> I've just reading about navigability on 115. page of UML2 
> Infrastructure, but I'm
> not sure what is key difference between: "non-navigable end" and 
> "unspecified navigability" ?
> Please, can someone explain this issue.

Hi Milan,

In a diagram, you may show an arrow, saying the association is navigable, 
or a cross, saying it's not navigable.  If you do not show anything, the 
diagram does not specify the navigability   ---   but the model itself 
ultimately determines whether the association is navigable or not.

At the metamodel level, there is no three-state logic for navigability: 
you either include the association end in the navigableOwnedEnds 
(meta-)association of Association, or not, by which you say it's not 

That's what I see in the UML specification (infastructure and 

I would still be interested to see how to handle "unspecified 
navigability" (and un-specification in general) while a model is created: 
   "I have not specified yet whether this association is navigable, I want 
to get back to this later".

Which is quite similar to "I have not yet decided whether the list of 
attributes of my class is complete - I want to get back to this later".

Anybody knows about the proper way to handle this - marking model elements 
as "not yet completely specified" ?


> _____________________________
> Best regards, Milan Milanovic
> M.Sc. candidate
> GOOD OLD AI Research Group
> Faculty of Organizational Sciences
> Department of Information Systems and Technologies
> University of Belgrade
Received on Sun 26 Nov 2006 - 09:24:34 GMT