Chapter Corner

Building Information Modeling

Posted in: Features, September/October 2013

BldgBluprnt.gifIndustrialization of the construction industry is happening everywhere. Building information modeling (BIM), simulation, computer-aided design, and many other product and process modeling technologies are becoming daily requirements in the construction industry. Managing complex and fast-paced jobs and prefabrication have increased higher demands on modeling. BIM has revolutionized the industry as a solution for product modeling, allowing for better integration between the parts and pieces that come together for building. However, the new wave of technology will focus more on process and information modeling beyond the building components and toward the builders and their work requirements. To stay competitive plus take advantage of the cost savings afforded by use of this technology, they need to be able to build a strategy to use BIM, product lifecycle management (PLM), and three-dimensional (3-D) experience within a virtual construction environment. The product models require input from engineers and designers to lay out the building. The new process models must include the input of the worker to be effective.

Up until now BIM has been primarily used and advocated by architects and engineers. The input from subcontractors has been limited to As-Builts and replacement of the paper blueprints. At best, the clash detection and coordination are now done in a virtual environment where previously it had been done physically in the field (e.g. “your pipes are in my way” and “the structural layout doesn’t match my drawings; now I have to do rework”). But it is not always successful. For example, in a BIM project in Seattle, WA, (Figure 1) the electrical contractor had to bend eight 4-inch feeder conduits three times each because the concrete slab openings did not line up between floors, and this went on for four floors. Or in another BIM project in Virginia Beach, VA, the sprinkler pipe clashed into the cable tray, leaving no space for the wires to be laid down, adding a few extra hours to cut the tray for the sprinkler pipe to clear it (Figure 2).

Without the productivity tools available to these contractors, these two projects would never know what hit them. Even these examples are still related to the product-related clashes that are not caught if the model does not include input from the tradesmen. The new wave of modeling will require even more input as the models start to include additional dimensions related to time, cost, and quality of installation.

The question still is what is in it for the subcontractor in applying BIM? As it stands now, nothing. But if we look at it from an internal usage perspective, much can be done with 3-D modeling, which can use any of the products out there. The new entrance of Dassault Systems in the construction industry early this year has given additional capabilities for sub- contractors to use the modeling tools to their advantage.

Few electrical and mechanical contractors have taken the opportunity of electronic modeling one step further by using it internally for prefabrication and Externalizing Work®. The very high-level and, most of the time, incomplete drawings will be used to create two- and three-dimensional fabrication drawings, enabling the contractor to externalize as much work as possible. Some electrical and mechanical contractors have been able to Externalize Work® up to 90 percent. Using point measuring equipment and transferring the data to the existing BIM model assures higher accuracy of prefabricated material for installation. The recent entry of Dassault Systems shows the importance of the usage of these tools to improve productivity in the construction market and a shift toward industrialization that other industries underwent decades ago. Electronic modeling and application will within a few years entirely change the landscape of the contracting work environment.

For example, Figure 3 shows a 3-D model prepared with jobsite information using some of the labor scanning equipment to create shop drawings for prefabrication operation. The figure actually shows an overlay between the model and the final install. Figure 4 shows the final pipes getting ready to be delivered to the jobsite. By using these techniques the electrical contractor was able to reduce the cost of labor per dollar sold from 43 percent down to 36 percent; a very significant amount of savings. In addition, due to better control of the material, the amount of material used for the job was better than 5 percent lower than the estimated amount.

Modeling, prefabrication, document control, and productivity measurement tools can help the con- tractors to reduce their cost of labor and material by better than 30 percent. The available technologies such as CATIA®, ENOVIA®, JPAC®, SIS® can help the contractors to be much more profitable and secure more work for their employees’ job security. The skills of the electrician must be used to help improve the models and prefabrication layout.There have always been faster, cheaper, and better tools for contractors to do their work. The new technologies of modeling offer the same thing. However, just like the drill in the gang box, modeling can only be advantageous internally if there is a companywide strategy for why and how modeling will be used to reduce the cost of installation. On the horizon of technologies that can go beyond product models and into process and information models that will optimize workflow, understanding how to translate the skilled trade know-how into the model will be critical.

Dr. Perry Daneshgari is President and CEO of MCA, Inc. Dr. Perry has published numerous articles for the industry and several books. The most recent books that Dr. Perry has published are: “Agile Construction for the Electrical Contractor” and Application of ASTM E2691, “Standard Practice for Productivity Measurement.”

Heather Moore is the Vice President of Operations at MCA, Inc. and a contributing author for “Agile Construction for the Electrical Contractor” and co-author for Application of ASTM E2691, “Standard Practice for Job Productivity Measurement.”

Dr. Daneshgari and Moore’s session, “How to Use BIM to Your Advantage and Reduce Cost,” will take place Thursday, September 26 at 1:15 p.m. at the 56th Annual IEC National Convention & Electric Expo in Portland, Oregon.