Virtual building blocks

Before General Motors broke ground on its Lansing Delta Township automobile manufacturing plant on Jan. 30, 2004, the 2.4million-square-foot facility had already been designed, built and equipped -- in cyberspace. Before the first shovel of earth had been turned at the physical building site, the Detroit automaker created a virtual factory -- a complete, 3-D version of the plant and its contents.

Architects, contractors, subcontractors and GM's facilities, manufacturing and production staffers collaborated upfront to design an integrated, multilayered 3-D model of the LDT campus, which included six buildings. They then worked together to iron out conflicts between the different building systems and the production process equipment within those buildings, assembled the finished structures, and scheduled the construction.

The new US$1.5 billion facility, which opened in June, was completed faster and with a better safety record, higher quality and lower cost than previous projects, says Jack Hallman, director of capital projects for General Motors' Worldwide Facilities Group. 3-D "is going to revolutionize how we construct our buildings," he says.

But the technology is really an evolutionary step at GM, which already uses 3-D tools in the design, manufacturing and production of cars. "The architectural engineering side is merging with the process side," says Kirk Gutmann, global information officer for manufacturing and quality. The building has become an extension of the production process, a wrapper into which existing 3-D models of the manufacturing operation can be inserted. "These are techniques we've learned in the manufacturing end of the business, and we are applying them to the construction business," Hallman says.

"Our design and manufacturing is now integrated into the same digital pipeline," says CIO Ralph Szygenda.

The results exceeded GM's expectations. The project came in 5 percent to 8 percent under budget and 25 percent ahead of schedule. That made it possible to get new vehicles produced at the plant and into the market faster, Hallman says. And the efficiencies of 3-D design could eventually change the way buildings are designed and built for any business, he adds. That said, the architectural engineering firm, contractors and GM staffers all report that the initial learning curve presented some challenges.

The 3-D modeling tools used for building information modeling are as mathematically precise as the mechanical engineering tools GM uses to design and manufacture its products. Although 3-D tools have been around for some time, they have only recently evolved to become "production worthy," says Robert Mauck, vice president of advanced technology at Ghafari Associates LLC, the Dearborn, Mich.-based architectural engineering firm that led the LDT project. "In the last few years, you've really started to see this stuff work," he says.

The tools have gained acceptance for plant construction in some fields, including the petrochemical and aerospace industries, but have yet to catch on in a big way in the general building trade. The software creates precise engineering drawings of a building and its various elements at scale. Building systems -- electrical, structural, mechanical and so on -- are integrated into the model in layers. Instead of looking at separate 2-D drawings and guessing how they fit together, the design team can integrate everything into a single 3-D image. At GM, those 3-D models were projected onto a wall screen in a virtual assessment room during weekly meetings. Participants then did "fly-bys," navigating through the virtual building to identify problems. The software also automatically identified "interferences," such as heating, ventilation and air conditioning (HVAC) piping sections that collided with steel truss work.

GM's facilities group first turned to 3-D in 2003, after management challenged it to come up with a way to build the company's next plant 25 percent faster and at a lower cost than it had in the past.

GM formed a team that included its facilities, manufacturing and production operations; Ghafari Associates; general contractor Alberici Constructors; and several other contractors and subcontractors. Ghafari created the baseline model using MicroStation design software from Bentley Systems. An integrated model created using JetStream software from NavisWorks performed automated interference detection. Participants could check out, edit and check in layers of the model for which they were responsible and view them within the overall reference model.

While Ghafari created the basic building framework, contractors were responsible for updating and uploading into the model the components they were designing, fabricating and installing -- from structural steel to electrical and HVAC systems. For example, Alberici took the basic model for the steel structure and added the detail necessary for fabrication, right down to individual plates and bolts, and then fed it back into the NavisWorks model. The idea was to resolve conflicts in the model rather than in the field, where change orders can add 10 percent to 15 percent to a project's cost. Aberici could then download the final data to its cutting machines and use it to automatically fabricate the materials.

GM and the contractors were skeptical at first. The construction trade is slow to change, says Paul Lemley, senior vice president and general manager at Alberici. "We use a lot of the same techniques that they used to build the pyramids," he says only half joking, adding that it took the industry nearly 20 years to totally accept computer-aided design systems. Alberici had used 3-D tools before, but "we were a little skeptical about using [3-D] at this scale," he says.

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