BIM and oBIX (UNCLASSIFIED)

Classification: UNCLASSIFIED

Caveats: FOUO

Recall that last week I uploaded a new draft document  that provides an abbreviated example of how oBIX information is represented in a BIM using the BAMie (Building Automation Modeling information exchange) specification.  We’ve talked
 about including some BIM information in 2.0, and I imagine this to be a lightweight integration that simply relates the data points to equipment in an open BIM model.  BAMie, in many respects, is a similar sort of integration, but from the BIM side instead
 of the oBIX side. I want to provide some background information about how this integration is tackled on the BIM side to setup future conversations about oBIX 2.0 and BIM.

 

If you opened my example file without any prior experience with BIM then you may have thought, “A spreadsheet…what?”  (https://www.oasis-open.org/apps/org/workgroup/obix/download.php/48618/2012-03-20-Duplex-BAMie.xlsx).

 

So, what does a spreadsheet document have to do with BIM?  The answer is that this spreadsheet format was prepared according to the Construction Operations Building information exchange (http://www.wbdg.org/resources/cobie.php)
 (COBie) standard.  The COBie format is a buildingSMARTalliance standard that was introduced as a way that valuable data from BIM models may be presented in a file format that is useful for building operators, owners, and occupants – afterall, only architects
 and designers have the expensive software that authors the CAD/BIM models.  The COBie format is also mapped to the Industry Foundation Class data model (ISO/PAS 16739) (IFC), the de-facto international data standard for representing CAD/BIM models.  COBie
 data presents only a small subset of the information that could potentially be in an IFC model and is primarily a specification of the building’s logical decomposition (floors, zones, spaces), location of equipment, warranty information, links to equipment
 manuals, etc.  There is also a COBie XML schema emerging (http://buildingsmartalliance.org/index.php/projects/cobielite/) that is MUCH more accessible to programmers – unless you
 know application developers that prefer spreadsheet data bindings to XML schema.   

 

Because the IFC data model supports several application domains (HVAC, electrical, water, audio/visual, architectural) it is an enormous data model with over 700 entity types and more native types, property set templates, etc.  So, model
 view definitions (MVD) are also defined to specify exactly how the IFC model should be used to model specific information exchanges – e.g. design coordination, facility management handover.  Recently the draft BAMie model view definition was released (http://www.buildingsmartalliance.org/index.php/projects/activeprojects/180). 

 

The BAMie model view specifies how to represent the logical and physical connections between automation/monitoring equipment and the building, logical/physical connections between the automation/monitoring equipment, automation/monitoring
 product information, addressing information (for accessing data), equipment configuration information, and summaries of performance data.

 

In my BAMie example there are a number of columns and tabs that are not relevant to this discussion, so I color coded the “interesting” worksheets in red.  The example is simply showing how I am representing the following automation/monitoring
 facets:

·       
3  product “Types” that occur in a building:  a receptacle, energy sensor, and a controller 

·       
Occurrences (Components) of these equipment types that are placed in specific rooms (Spaces) in the data. 

·       
There is a logical grouping of the automation system components (System).

·       
Links to oBIX data points corresponding to the sensors (Document).

·       
Physical connections between the Components (Connections)

 

So, how much of the BIM to we model in oBIX 2.0?  Do we assume that the sensors are modeled in the BIM, thus relating them to rooms/other components, or do we assume that we will only get spatial decomposition from the BIM?  It’s all up
 for discussion on our road to oBIX 2.0.  

 

Chris Bogen, Ph.D.

Computer Scientist

US Army Corps of Engineers

Engineer Research Development Center

Vicksburg, MS

 

Classification: UNCLASSIFIED

Caveats: FOUO