Second day at CFTA 2011 Conference

I love standards, in theory.  In practice, there's never anything standard about them.  COBIE2 is no exception.  While specifying the interchange format (Excel spreadsheet) and the data in the model (features) is great, what's totally "ungreat" is the flexibility of user-defined columns.  Which is really all useful columns, since only the most basic columns are in the COBIE2 standard.  I predict this is going to bite someone, so let's play out a scenario.

Imagine a contractor gives a COBIE2 spreadsheet to NCSU, and NCSU uploads that COBIE2 into AERES, and AERES updates its models accordingly.  Great, interchange has happened.  Now, imagine NCSU wants to pull that COBIE2 out and send back to the designer.  What does AERES do?  Does AERES give back only the fields in the standard?  Or only the fields it was originally given?  Or all fields?  Or let the user choose?  And then, what does that other software do when it doesn't support the incoming fields?

This is what we engineers call an impedance mismatch.  One side is unprepared to handle what the other side is giving.  Since COBIE2 is only the definition of an interchange format - and not the definition of the process behind that - there is no way to uniformly reconcile what should happen.  Right now, I'm going with Postel's Law: be conservative in what you send and liberal in what you accept.  But this isn't the only impedance mismatch: what happens when the model changes, say area increase from 100 units to 200.  What does the design element of the model do?  Does it explode the polygon?  Does it emit a clash warning?  I don't know, but it won't be pretty.

What is pretty is all the mechanical works under the Smithsonian's National Museum of the American Indian and the monuments at night.  Fun fact: GSA provides chill water for all the Smithsonian along Independence Avenue.

Thanks to CFTA for organizing these tours, ESRI for hosting tonight's reception in the fabulous Smithsonian Castle, and congratulations Smithsonian Institution on earning your LEED Silver!