| [railML2] Change of wording for TT:004 and TT:005 [message #3508] |
Tue, 11 March 2025 17:56  |
Milan Wölke
Messages: 213
Registered: April 2007
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Senior Member |
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Hi all,
During a past certification we noticed that the semantic constraints TT:004 and TT:005 have been worded too strictly. They make sure that rostering and blockPart either reference a vehicle or a formation and not both. However there is cases where actually it does make sense to provide both without a contradiction. In particular if the formation consists of only a single vehicle and that vehicle is referenced via vehicleRef.
We discussed this in the last timetable developer group meeting and decided to change the semantic constraints to the following wording:
<rostering>
Quote:vehicleRef and formationRef are to be used exceptional since the circulation plan is either one for a certain vehicle or one for a whole formation. The only exception to this rule is if the formation consists of only one vehicle that is also specified via vehicleRef.
<blockPart>
Quote:
vehicleRef and formationRef shall not be used within the same blockPart, since a blockPart is either one for a certain vehicle or one for a whole formation. The only exception to this rule is if the formation consists of only one vehicle that is also specified via vehicleRef.
The timetable developer group approved this change. Do you have concerns? Please let us know what you think.
Best regards, Milan
Milan Hoffmann – Timetable schema coordinator
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org
[Updated on: Tue, 11 March 2025 17:56] Report message to a moderator |
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| Re: [railML2] Change of wording for TT:004 and TT:005 [message #3519 is a reply to message #3508] |
Thu, 20 March 2025 16:10  |
Thomas Nygreen
Messages: 110
Registered: March 2008
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Senior Member |
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Dear Milan,
First a question, regardless of the change: as the @vehicleRef and @formationRef of the <rostering> are inherited by its <blockPart>s, how is TT:005 interpreted for combinations of attributes on the <rostering> and <blockPart>?
Then to the proposed change: I agree that the presented case does not involve a contradiction, but is it a meaningful extension, or does it only complicate the validation? As the vehicleRef already can be obtained from the formation, why would it be necessary or useful to also include it in the <rostering> or <blockPart>?
Finally: "to be used exceptional" should be changed to something like "shall not be used together".
Best regards,
Thomas
Thomas Nygreen – Common Schema Coordinator
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org
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| Re: [railML2] Change of wording for TT:004 and TT:005 [message #3534 is a reply to message #3519] |
Fri, 28 March 2025 14:18 |
Milan Wölke
Messages: 213
Registered: April 2007
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Senior Member |
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Hi Thomas,
Thanks for your valuable input. I will adapt the wording you proposed, it makes it easier to understand without changing the meaning.
Regarding the question if it is a meaningful extension to allow specifying both if they do not contradict. As per what I understood from the developer group it is a meaningful extension. Some systems are working based on circulations of formations while others track individual vehicles. If it was not possible to specify both then the same circulation would need to be described twice in order to provide input for both kinds of importing systems.
Regarding your 3rd question, that is a good point. I dont think right now we have regulation for this. I will add this to the agenda of the next timetable developer group meeting and discuss it there. It may make sense to introduce yet another semantic constraint for this.
Best regards, Milan
Milan Hoffmann – Timetable schema coordinator
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org
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