Thursday, April 27, 2006

AutoCAD vs. ABS vs. Revit Systems

We have more choices everyday whether we want them or not. Remember when there were only four television stations? NBC, ABC, CBS and public TV. As a kid I remember when the President’s State of the Union address would come on. “Oh man! The President is on! Now I have to watch a documentary on Barn swallows." Some of you may be too young to remember life before cable, but I bet most can remember a time when your choice of CAD technologies was limited to one.

Digital Drafting
Whether you liked AutoCAD, MicroStation, or whatever. (I was a big fan of Mac Architron.) The technology they all used was the same. Digital lines. We still drafted, but with digital lines. These lines could only be differentiated by color, linetype and layer. So we made a mess of layers to control them.

Object Oriented
Then came ADT and ABS. This was revolutionary. Instead of digital lines, new entities called objects were introduced on the AutoCAD platform that contained specific properties to the object type. Doors have properties like height and width, diffusers in ABS have properties for flow. These properties allow us to step away from layers for display control and give us a mechanism for linked scheduling of any object type. As an added bonus, these objects are three dimensional which gives us relational clean up when similar objects meet, like duct and pipe, and interference detection when differing object types occupy the same space.

Parametric Modeling
Revit Systems and Autodesk’s other Revit based programs take a giant step ahead of digital drafting and object oriented technologies by creating a relational model that can be queried for any type of view, schedule or detail. How many times have you heard draw it once? The minute you draw it twice in AutoCAD or ABS somebody changes one of two and now, there’s a disconnect. A Revit project has only one model. You can only draw it once, literally. Further, it does not matter which view of the model you modify, all views update because they are all referencing the same thing.

Let’s compare these three technologies in a little more detail.

AutoCAD 2007

-Highly adaptive to most any drafting use.
-It’s the standard.

-Highly customizable.
-Large pool of qualified users.


-It Crashes too much.
-Can’t complete against Autodesk’s vertical products.
-Requires implementation, optimization and administration to be truly effective.

Bottom Line
You know what you got with AutoCAD, it’s comfortable, but I can visualize a time when the building industry uses AutoCAD about as much as we hand draft now.

Autodesk Building Systems (ABS) 2007

-It’s plain faster to drop in a complete object in a drawing that automatically connects to objects around it than draw line by line.
-ABS will draft AutoCAD into the ground when properly set up.
-The ability to import and export engineering data to familiar software for engineering calculations.
-Sections and elevations cut and schedules created in just seconds.
-Interference checking between ABS objects and ADT structural objects.

-Familiar Interface lures un-trained users to fall back on AutoCAD tools and procedures effectively negating the additional cost.
-Near impossible to implement without an experienced consultant.
-Training is required to effectively use ABS.

Bottom Line
It's the best thing we have for MEP engineering right now. Knowing AutoCAD is not a free ticket to understanding ABS. It goes a long way toward reducing redundancies but still requires manual updates between related design components.

Revit Systems 1
-Advanced Engineering capabilities include Load Balancing, Lighting Levels, Voltage Drop and Pressure Loss.
-Bidirectional Associativity.
-A single data base means I get accurate associations between all my data, all the time.
-I have never crashed Revit… Ever.

-Did somebody forget Plumbing? Tap, tap… is this thing on?
-Very, very few qualified users. Those who invest in learning how to reap the rewards of Revit Systems will have to be compensated.
-This is the first shot out for Revit Systems, no matter what they got right, you can bet there is going to be a list of things that will need to be fixed or added.

Bottom Line
A true Building Information Modeling solution. If I am going to dream about where BIM can go, currently Revit products are the best the building industry has to offer.

If you want to be on the cutting edge, jump on now.

Wait much longer and you will be playing catch up while your competition is widening the gap between the future (everybody else) and the past (you).

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