In Re-fabricating Architecture, Stephen Kieran and James Timberlake talk about pre-fabrication and contrast the AEC industry with the OEM industry. What they don't provide is a solution for reconciling initial cost with total cost. When the schedule is compressed, and money is not available to accelerate it, how does the CM deliver the building on time and at budget while maintaining its standards for quality and safety?
Any solution requires additional CM/TC input at the design table. As a tenant comes on board and wants to change the design, the CM in the past has accepted the change at its face-value. The change is often documented in plan, and if the CM is lucky, in section.
Prior to a model-based workflow, it was nearly impossible to account for every upstream and downstream impact to the design change. The resultant vector usually ended with inflated estimates, rework, and additional costs through completion to accommodate the downstream trade contractors. The CM, in turn, becomes the villain for not perfectly anticipating every impact.
However, the use of the model-based workflow, design model coordination, and TC involvement with the architect during design development allows the CM to provide the designers and the owner/tenant with very near real-time estimates. These estimates very well could come in higher than estimates in the previous process, but they also more completely capture the total scope of the change. The question then becomes: Is it more preferable to rip the band-aid off in one motion, or pull at it one millimeter a day for 8 months?
2D documentation of a typical change to add additional beams below an elevator:
-No depth to documentation
-No coordination with architect with regard to building code
-Omni-directional information flow - limits ability to 'read and respond' to change
-Finally.....Makes the eyes bleed.
3D documentation of the same change by CM
-After fire-spray and soffit to protect elevator equipment, room does not meet building code for head height clearance
What we've seen to-date is that the decision makers get sticker shock because they're working from a poor baseline of experience and documentation. Very rarely is the entire change-order log digitally re-integrated with the initial estimate to determine the full cost of a job. What should be a closed feedback loop is inherently incapable of metastasizing during a full project life-cycle (there is just too much information to process in analogue). This, in effect, poisons the next job, because the project teams accept an incomplete and inefficient process as a success, as long as the building is finished.
So what is the solution?
Firstly, there is simply too much information to handled by humans, notepads, and 36x48s. Project teams need databases, not drawings. Decisions should be made with the maximum information at hand.
Secondly, design teams need to get away from the 'ambiguity through obscurity' of 2D documentation. If the A/E team refuses to document scope in 3D, the CM is going to do it anyway, and use that authoring power to drive the design in its interest.
--Myers
So what is the solution?
Firstly, there is simply too much information to handled by humans, notepads, and 36x48s. Project teams need databases, not drawings. Decisions should be made with the maximum information at hand.
Secondly, design teams need to get away from the 'ambiguity through obscurity' of 2D documentation. If the A/E team refuses to document scope in 3D, the CM is going to do it anyway, and use that authoring power to drive the design in its interest.
--Myers
