To the great puzzlement of BIM enthusiasts, the construction industry has largely not latched on to BIM. It's been two decades, so what's the holdup?

BIM enthusiasts have their favorite solution: get government to force BIM on everyone, starting with architects and going all the way through to building operators. (It's already been done in England.) That BIM might not be optimal for certain phases of a building's life is left unexamined. It's technology, so adapt already.

The MCAD industry has taken to CAM, but the AEC industry has few equivalents. CAM [computer-aided manufacturing] works well in architectural projects that are predictably uniform, such as kitchen cabinets (my new ones were cut that way) and prefab houses being built inside warm, dry warehouses. But for most buildings, the construction conditions are non-pristine.

I use the analogy of building a Boeing 747 aircraft out in a muddy field, with each aircraft designed to be different, and being built in different cities. The inefficiencies in building construction (that some say can be driven out)  can, in fact, not be driven out. 

White-watering With Canoes

Lucy Suchman uses a different analogy. She describes whitewater canoeists coming upon rapids. As they look over the conditions, they plan their paths around boulders, through fast water, and past eddy currents. "A great deal of deliberation, discussion, simulation, and reconstruction may go into such a plan," she writes. 

Then they set off. 

However detailed, the plans stop short of the actual business of getting the canoes through the rapids. When it comes down to the reality of responding to currents and handling the canoe, we effectively abandon the plan and fall back on whatever embodied skills are available to us.

Ms Suchman wrote Plans and Situated Actions: The Problem of Human-machine Communication 30 years ago to warn us that our careful, thoughtful planning is limited in determining outcomes (to quote book reviewer Andrew Yuengert). Ms Suchman is professor of Anthropology of Science and Technology at Lancaster University in England. Before this, she was at Xerox's fabled Palo Alto Research Center for 22 years, as Principal Scientist for some of that time.

Today her primary research is in situational awareness: how people react in real time to changing conditions, particularly on battlefields. Ten years ago, she updated her book with a new title, Human-Machine Reconfigurations: Plans and Situated Action, and five more chapters. 
 

Construction Takes BIM on a Canoe Trip

BIM and construction are like the canoe trip. BIM takes place at the head of the rapids, where the ideal route is planned out. Construction takes place in the rapids, where the unexpected and the unplanned is the norm -- these are the situated actions (a.k.a. embodied skills). 

Contractors with experience have embodied skills that designers lack; contractors gain the skills by tackling the unexpected daily on-site. This is the reason that "as-builts" are part of the BIM process: they correct idealized plans with the real world results.

BIM can make predictions of what should result on the building site, but it does not know what will occur. Worse, it cannot know.

In the end, BIM cannot be in charge of construction; construction is in charge of BIM.

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