The Turner project team working at Three White Flint North, the 14-story, 366,000 square foot future home of the Nuclear Regulatory Commission in Bethesda, Maryland is using Lean construction methods including Building Information Modeling tools to reduce waste and rework and improve operational efficiency.
The team and trade contractors are using 3D, digital models to identify and resolve clashes and other issues prior to construction. The trade contractors are also using 3D, digital models to produce shop drawings, leveraging the 3D data to prefabricate system assemblies off-site. Off-site fabrication reduces material waste and transportation costs. Because they are able to fabricate off-site, trade contractors can deliver material and systems on a just-in-time, as-needed basis, which allows for a more controlled and predictable installation process on-site.
The Turner team is using a combination of 4D schedule visualization – linking the model to the schedule— and the Last Planner System™ to conduct collaborative “pull” sessions with trade contractors. This scheduling method identifies interdependencies between construction trades, working backwards from project milestones. During these “pull” sessions, each trade drives out hidden buffers and contingencies by committing to produce and install only what the next trade requires. The Last Planner System™ is one of the primary tools in Lean construction for making jobsite processes more predictable.
The team is also using Turner c.docs, a construction-phase, digital document management system which has helped them minimize printing and shipping costs. Turner c.docs has also helped to make information more readily available in the field, enabling more rapid and informed decision-making. Digital construction documents, which can be viewed on mobile computing devices, mean that when the team refers to drawings they know not only they are referring to the latest, conformed set, but that all other members of the team are referring to the latest set as well.
The Turner team at White Flint North is using technology as part of a larger, Lean methodology to create a culture of continuous improvement on their site. They know it is important to evaluate all processes and workflows to identify where process improvement methods like Lean can be applied.