I am working on an article on BIM for MM&T, an online resource for the AEC community. One of things they'd like me to address is my (and Tocci's) idea of the ideal practice for a design-bid-build job:
We, along with several other contractors are invited to bid on a new project. The next day, the architect sends us the complete Revit model, containing components from Revit Building, Revit Structure, Revit Systems & 3D Civil, and the e-Specs file.
The department administrator sends the model and e-Specs file out to subcontractors for pricing. The e-Specs file allows our team and subcontractors to easily review the specifications and view the places in the model that each specification section applies to.
Meanwhile, the other team members work on extracting quantities for an internal takeoff and scheduling the model. This work may be done in Revit or Navisworks.
After the quantities are extracted, they are linked to the Timberline estimate. An estimate populates, using Timberline's GC databases. As bids from subcontractors start coming in, we already have quantities and pricing to compare to.
Once the model is scheduled, we will produce scheduling deliverables which will later become contract documents: an AVI file that shows what looks like a movie of how the building is going to built and a series of images, showing what the building will look like at specific dates during construction.
We will also use Revit to come up with some suggestions for value engineering (VE). We can compare design options in Revit & then extract the associated quantities from the model. This allows us to present multiple budgets to the owner.
After we win the job (because with accurate and user-friendly deliverables like those described above, how could we not), the project team (designers, subs & team Tocci) would have a meeting to review model sharing strategies, chain of communication and VE items.
From there, the subcontractors each develop and then submit a model (instead of shop drawings) for their trade, basing it on the designer's model. Those models are merged in NavisWorks and then used to develop a clash report. A series of coordination meetings and model updates resolve the issues that were brought up in the report. If all of that is done correctly, it should greatly reduce the number of field coordination issues as well as the number of change orders.
We will also continue to use the model for scheduling and quantity takeoffs. The visual schedule will allow us to easily compare the actual construction progress to the schedule. We can also update the model to reflect actual construction progress. With respect to quantity takeoffs, we can notify the superintendent and subcontractors the quantities of items they will need onsite each day, enabling them to take advantage of lean construction principles.
As we proceed, I'm sure we will find dozens of other ways to use BIM. The difficult part is figuring out how to share the model and collaborate with other project partners.
We are years away from being even close to this; out of the 43 architects that are designing projects we are building or planning to build, only 2 have provided us with architectural 3D models. Maybe 2-3 more have approached us for advice as they consider using Revit or another 3D intelligent modeling program. Out of the thousands of subcontractors in our database, only a few are using 3D intelligent modeling. We have yet to recieve any models from any of them.
Well, it's nice to dream.