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Subject: oBIX 2.0 and SOA and WS-Calendar

I will be submitting some specific comments about semantic mis-matches between oBIX and WS-Calendar as part of the 1.1 PR01. That will take more time and careful thought—especially as maintaining compatibility with existing base is paramount.


This is *NOT* that conversation.


Part of oBIX 2.0 is the introduction of more Service Oriented notions to Building Systems. We often use those words with some imprecision. I would like to recommend some readings to make sure we are all on the same page. A good understanding of the SOA Reference Model, including how different it is from the way that control systems are traditionally integrated is necessary. I recommend that folks read the excellent, clearly written discussion of SOA prepared by the soa-rm TC. It is technology and transport agnostic, and will establish a common vocabulary for us going forward.




Some key aspects of SOA is that it is results oriented mechanism agnostic. I always like to use a classic calendar interaction to illustrate. Several of us receive a meeting request for 9:00 next Tuesday. We all accept. One must pack lunches and take the kids to school first.  One attendee must walk the dog, first. One attendee who usually telecommutes must find and wash a pair of pants to attend. One attendee must schedule a flight, and book a hotel room. One attendee merely stretches after his 8:00 meeting in the same conference room. The service we all agree to is being in the conference room from 9:00 to 10:00. The interaction, though, hides the complexity and the diversity.


So how does this apply to oBIX?


Setting a schedule for building operation could be like inviting a person to a recurring meeting. Many of us invite the conference room to meetings, just as we invite people—we never tell the conference room itself, or rather the BAS behind the conference room that we expect 20 people at 8:00 AM. Office occupants may decide to build business by having an open house next Thursday night, which may affect not only the meeting room but the lobby and public spaces as well.


I have discussed scenarios similar to this with many experienced BAS integrators. Right away they say “well that’s straight-forward.” The Administrative assistant just has to put the conference room in occupied mode [30 minutes] [ 1 hour] in advance. This sort of process knowledge is outside the scope of the office worker. A service interaction would put the BAS in-charge of the pre-cooling period, not the people who have other jobs.


A WS-Calendar interface to a control, if advertised, would state if it is able to meet such a service expectation.


A key element that I glossed over above is the number of attendees. When you and I receive a meeting invite, we can see how many were invited. A room with only a couple attendees may be too cold. A room with many attendees may be too warm, and without enough air. Folks shiver for the one-on-one performance review, and fall asleep during the all-department meeting. What expectation does an oBIX 2.0 Service that claims conformance to WS-Calendar have for information about capacity?


As to links between BAS, and Rooms, and Space, I think those fall somewhere into the Metadata inquiries and contracts; whether tied to to BIMSie or to a simpler taxonomy, built into the BAS, and revealed by oBIX 1.1 metatags.  


This does hint at another conversation, about whether I can establish a contract with those control system points associated with a Room, but that is not this conversation.





"Energy and persistence conquer all things." -- Benjamin Franklin

Toby Considine
TC9, Inc

OASIS TC Chair: oBIX & WS-Calendar

OASIS TC Editor: EMIX, Energy Interoperation

SGIP Smart Grid Architecture Committee


Email: Toby.Considine@gmail.com
Phone: (919)619-2104

blog: http://www.NewDaedalus.com


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