Thursday, January 18, 2007

Collaboration, Disclaimers and Risk Management

From my old blog...

I've been inspired by a recent thread on the AEC-IS Roundtable forum to discuss the topic of collaboration, digital file disclaimers and risk management when employing Building Information Modeling tools. I recently met with Jim Bedrick, Director of Systems Integration for Webcor Builders in California to discuss related topics and I credit the inspiration for this thread to his Roundtable responses.

Most, if not all practicing Architects and Engineers use a Digital File Disclaimer when transmitting CAD files to clients, consultants and contractors. These disclaimers function as the buffer between the designer's intent and the builder's means and methods. To put it bluntly, disclaimers absolve the designer or engineer of any liability due to errors or omissions in their digital data. Most disclaimers also state that the accuracy of such data cannot be guaranteed. Where does this leave the state of efficiency in collaboration? See the NIST Report on Interoperability or Paul Teicholz' article on Declining labor productivity in the construction industry.

Think about what that means to a contractor when you send him/her your CAD files or BIM model and you state that none of the lines or model objects are guaranteed to be accurate. Guess where that data will go... Herein lies the problem: today's liability and insurance requirements restrict the Architect or the Engineer from dictating means and methods to the builder, thus we must take a more focused look at our methods of modeling and documentation in a collaborative environment.

While movements are underway to change the way projects are delivered, in effect distributing risk across an entire project team (result-driven), I believe the A/E sector can begin to re-examine its current collaboration process with upcoming BIM software. To begin, builders like Mr. Bedric are imploring designers to avoid 'fudging' practices such as overwriting dimension string values in CAD files or widely using terms such as "VARIES." If the A/E industry can formulate a loose set of best practices for BIM, we will make great strides towards improving productivity and the usability of our data by downstream consumers.

As far as production cost savings are concerned, Mr. Bedrick believes that reducing the time and effort required to produce shop drawings by reusing design CAD/BIM data is insignificant; however, true value can be harvested by efficient use of a RELIABLE digital model in order to provide faster, more accurate quantity take-offs. This would drastically reduce the turnaround time on estimates and would allow for either lower pre-construction fees or more frequent cost estimates which would potentially "reduce or eliminate value engineering efforts resulting in rework for the Architect."


  1. I remember hearing John Macomber speak at an AEC Systems conference in 1999 or 2000 talking about how the potential of new building industry software could be reached only if the industry rethought the way it assigned risk. He was way ahead of his time. I agree with him, but I fear that this is not easily achievable.

    The key word regarding using Digital Models in this posting is "RELIABLE." Unfortunately it seems that people who have sloppy habits in CAD will have sloppy habits in BIM. Whereas BIM eliminates the ability to produce an uncoordinated set of "orthographic projection" print drawings (a huge step forward), there is so much information that is invisible in the model.

    If a contractor is to use software to do quantity take-offs from a model & the results are inaccurate due to "garbage in - garbage out" in the creation of the model by the architect, who bears the liability?

    The same can be said to an extent about paper documentation, but unfortunately the more you automate a system, the less people pay attention to the actual processing of the information & the poorer their intuition becomes in recognizing that results are off base.

    The "Best Practice" regarding the use of this data is old-fashioned hand-checking. For example, I have seen many sophisticated Excel sheets used for zoning area calculations which are incredibly useful, but one invisible error in an equation can make the results way off base. An experienced eye can tell when the numbers don't look right, and a seasoned professional will do a hand-check of the results. Those that depend too much on the computer to do their thinking for them inevitably are prone to creating serious mistakes.

    As a poster on the wall of the computer room at my High School in the 1970's read, "To err is human, to really screw things up requires a computer."

  2. Your article is very informative and I request you to provide another article on "Creation of quantity take-off from BIM Model" which will be very helpful for our site