| Re: new draft of <infrastructure> 0.94 [message #16 is a reply to message #14] |
Tue, 02 September 2003 06:32  |
Vasco Paul Krauss
Messages: 27
Registered: July 2003
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Junior Member |
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Liebe Kollegen,
die untenstehenden Nachricht sende ich im Auftrag von Herrn Thomas
Kauer (SBB, Schweiz), der wegen Firewallproblemen nicht direkt in
Forum schreiben kann.
<english>
I post this message on behalf of Mr. Thomas Kauer (SBB, Switzerland).
</english>
On Thu, 21 Aug 2003 13:17:11 +0200, "Matthias Hengartner"
<mhengart(at)studentethzch> wrote:
> I have an additional comment on my proposed schema:
>
> I've added an ID-attribute to all lineElements for the unique identification
> (which is necessary e.g. for visualisation) of a lineElement within one
> track. So we can identify a lineElement globally using the combination of
> lineId, trackId and ID.
>
> Alternatively we could also define that the ID of any lineElement has to be
> globally unique.
>
> I think that the former idea of identifying lineElements by
> lineId-trackId-pos has the disadvantage, that there can't be 2 or more
> lineElements on exactly the same position (or is the occurrence of this
> situation not feasible?). That's why I added the ID-attribute.
We are also discussing the problem of a global id.
In our actual systems we know the problem of different elements at the
same
position and had to introduce an artificial offset - so the postion is
not
always helpfull.
Furthermore we have the goal to make the difference between different
states of an element so that we can manage the whole lifecycle:
- first introduction of an element within studies (many parallel
versions
for the same line!)
- refinement (of one or more versions) for concrete projects
- final construction plans
- in construction
- build (not yet in use - testing)
- in use
- deconstruction
- history
So to identify an element we should be able to address the state we
are
looking for. Each state should have a time of validity.
An other problem when using the position of an element for it's ID:
During it's lifecycle the postion of an element can be changed
(normally by
a small amount) without the need of changing it's ID or usage.
Best regards
Thomas Kauer
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