This blog is adapted from an AIA presentation on Technology and Practice presented in partnership with the UNC Charlotte College of Architecture in October 2016.
Research indicates that construction is one of the only industries where efficiency and productivity has actually fallen over the past 50 to 60 years. While processes exist to optimize construction, one of the biggest challenges in overcoming this inefficiency is the fact that few AEC companies see their own inefficiency.
According to the 2013 Dodge Data & Analytics (McGraw-Hill Construction) SmartMarket Report, roughly a quarter of U.S. general or trade contractors expressed familiarity with or had implemented Lean construction practices.
Significantly fewer still—less than 8%—had used specific Lean manufacturing strategies such as Toyota Way or Six Sigma. More interestingly, the report found that those companies not familiar with a Lean approach didn’t view their practices as inefficient.
The building industry as a whole remains a long way from understanding the efficiency benefits of Lean manufacturing in construction. And without this understanding, there’s limited opportunity to reduce the 30% waste seen across construction sites.
However, the journey to Lean manufacturing in construction has already begun and knowledgeable architects can further drive this transformation.
This journey can be seen taking place in three waves.
The 1st Wave: Design for Fabrication
One of the largest areas of waste in AEC processes is the creation of multiple redundant drawings.
Most architects today create 3D representational drawings from which they extract 2D drawings for the purpose of permitting or, in some cases, construction drawings.
In addition, the fabricator will produce detailed shop drawings that show every nut and bolt and exactly how every part they supply will need to go together.
Then the builder needs sequence drawings that show scaffolding, formwork, space for storage and equipment, and so on.
This is where much of the 30% waste comes from: redundant effort and coordination after the fact of these different files from different professional experts.
Consider how differently each trade looks at a single building element like, for example, a column.
- The architect focuses on the finished material, such as the brick or stone cladding.
- The structural engineer focuses on the overall shape, perhaps the concrete density, and an understanding of the load the column can bear.
- The structural detailer focuses on the rebar inside the column and the connections between the beam and the column.
- The builder focuses on the formwork that surrounds the column because that is the activity that must occur in the field.
- A facility manager focuses on the as-built conditions as well as the history of how the column got installed.
This may mean five different models created by five different parties with five different software packages that represent the same item in the building, all of which are important to the facility manager who looks at all of those combined viewpoints as important history about the column.
Few BIM solutions today integrate these various steps, focusing instead on the architect’s need to create a 3D drawing. Yet these steps can be integrated and done in a collaborative way.
With design for fabrication, all parties can further work to integrate cost and schedule information to get a complete work breakdown and meaningful information for managing a project.
The 2nd Wave: Design for Delivery
On the site of a traditional construction project, many delays occur due to the necessity of sequencing workers. When large sections are prebuilt in a factory environment, it’s possible to use less expensive labor that can work side by side, and in a much safer environment.
However, even factory prefabrication presents challenges.
The prefabricated components must account for the logistics of delivering the units to the construction site and onsite installation.
The design must consider factors such as: How heavy are the elements? How large are the elements? Is there an order to placing them?
Design for Delivery provides value by simulating the construction process as a digital mock-up and creating a production control system to execute. Integrating the design concept, the fabrication details and the sequence models in a true PLM backbone allows AEC professionals to go beyond meeting contract requirements by simply reducing errors.
With true simulation—down to the level of individual workers to account for safety and efficiency, and planned sequencing—all parties can achieve high value and savings.
The 3rd Wave: Design for Manufacturing and Assembly
The third wave is about building in information on manufacturing efficiency into the way buildings are designed. The starting point for Design for Manufacturing and Assembly is to think about how to optimize factory processes and then most efficiently assemble the modular elements in the field.
In this approach, designers must understand the capabilities of the manufacturer to design an approach to construction and delivery that accounts for the logistics of getting the product installed. For example, a prefab concrete panel might best be completed with rebar exposed on one side.
By using half completed panels, the shipping weight can be reduced, the need for formwork eliminated as the panels themselves can serve as formwork for the final onsite concrete pour, and onsite MEP connections might be more easily completed.
Prefabrication has proven popular as a way to improve worker safety and productivity, as well as product quality.
But a factory approach must also account for how best to transport and place modular elements. In some cases this might necessitate the combination of a remote, highly automated factory, near site fabrication of elements and onsite final installation of elements. These types of strategies can greatly eliminate waste.
New Processes to Support the Three Waves
While most new designers coming out of school today are trained in modeling tools, not all are gaining true insight into their role in waste reduction. Architects can optimize the AEC process by working closely with manufacturers, fabricators and subcontractors early on projects, and with integrated drawings.
To reach this end, however, AEC professionals will need to adopt new contract structures to ensure early access to knowledgeable suppliers and embrace project insurance that protects all parties.
In addition, architects can advise owners to budget for shop drawings earlier in the design process, so that design documents and shop drawings can be created simultaneously in a collaborative environment.
By breaking down siloes, tomorrow’s AEC professionals can manufacture even highly complex projects more efficiently than ever.