Construction is an industry that has been slow to embrace modern working practices. But some innovators are achieving productivity gains through the adoption of Design for Manufacturing and Assembly (DfMA). The concept takes several forms, including designing products while keeping manufacturing and assembly in mind and applying factory conditions to construction projects. In a recent report, consulting firm McKinsey called construction “ripe for disruption.” With DfMA, construction is starting to disrupt itself.
One company leading the industry’s DfMA revolution is Laing O’Rourke. Headquartered in Dartford, UK, the company designs, engineers and constructs some of the world’s most significant buildings and is proving that DfMA leads to better outcomes for the company, its clients, the industry and society.
After two decades spent working for prestige European automakers, Chris Millard transferred into construction, then became head of Engineering Excellence and technical director for Assets and Manufacturing at Laing O’Rourke.
“When the principles of complex automotive engineering, design and manufacture are transferred to construction, they bring about fundamental change,” he said. Central to this reformation is the growing practice of designing, engineering and manufacturing building components – from foundations to complete bathroom pods – in factories.
With the DfMA method, designers and engineers try to optimize the processes of manufacturing and assembly by beginning with the way they design products. This contrasts with traditional construction, where many components are made on-site, leading to decisions about how to make them fit that continue into the final construction stage.
“DfMA removes risk and increases quality,” Millard said. “Off-site manufacture using our own large factories means we work to structured processes.”
Instead, Laing O’Rourke fabricates as much of the building as possible offsite, in factories, and ships it to the construction site for assembly. Factory-precision parts, include the pre-cast floor and wall components, columns and beams, and complete room modules that comprise the building, are delivered from the factory. To achieve this level of DfMA, the company deploys cloud technology for collaboration and develops 3D digital models that incorporate grand architectural gestures, plus all the fine engineering details required to bring them to fruition.
“With this data, we can find value opportunities and building methodology improvements,” Millard said. “That encompasses making perfect components, adding certainty to logistics, and significantly reducing on-site labor.”
SAVINGS BY THE NUMBERS
At a cost of £14.8 billion (US$19.6 billion, €13.1 billion) and having consumed 100 million working hours, Crossrail is Europe’s largest construction project. When completed in December 2018, it will revolutionize London’s rail network and support citywide renewal, adding an estimated £42 billion (US$54 billion, €46 billion) to the national economy.
Two of Crossrail’s central London stations, Liverpool Street and Tottenham Court Road, were constructed by Laing O’Rourke. The platform at Tottenham Court Road station did not benefit from DfMA, as the processes were still under development, so it was built using conventional onsite construction methods. Construction of that station platform took 57 workers 82,800 hours to complete. At Liverpool Street station, using DfMA, almost identical work took a team of seven just 2,492 hours – an improvement of approximately 97%
“Across much of construction there is a lack of consistency and transparency of data exchanges, and that means collaboration is hampered. Without collaboration, innovation suffers and that impacts the industry.”Richard Kelly
operations director, buildingSMART International
Millard has seen the same levels of improvement on road infrastructure projects, where a rail bridge can be completed in just five days. On a 40-story apartment block, availability of pre-fabricated components allowed workers to complete each floor in six days, instead of the conventional nine, with a 60% labor reduction.
The key to success in DfMA, Millard said, is to re-sequence everything.
“Working with the factory to understand their challenges and introducing cultural change through the organization are crucial. It’s a long learning curve to move from centuries-old linear processes to concurrent collaborative operations. But, when you experience the payback in terms of productivity and profit, everybody – from stakeholders to interest groups, politicians to taxpayers – sees benefits.”
Becoming more efficient is critical as global populations grow. For example, management consulting firm McKinsey and Company estimates that the world will need to spend US$57 trillion (€48 trillion) on infrastructure by 2030 just to keep pace with global economic expansion. Professional services consulting firm PwC claims that achieving this will require an 85% industry expansion, creating jobs and wealth around the world. But skills shortages are hampering both growth and the ability to reach this capacity.
A British government report describes the problem as “a ticking time bomb” and predicts that, due to an aging population and a lack of new entrants, the construction workforce will decrease by 20-25% in the next 10 years.
BuildingSMART International, a non-profit organization that brings construction enterprises together in a technological community based on commonly agreed standards, is dedicated to tackling these challenges. The group has 18 chapters around the world, comprising some of the industry’s biggest and most innovative players. Richard Kelly, the organization’s operations director, sees buildingSMART International as a key to meeting future demand.
“Our members comprise industry visionaries who are transforming the design, build and operation of buildings and infrastructure,” Kelly said. “They know that when high-value assets are created by a fragmented industry, change is required to avoid waste, quality issues, cost overruns and late delivery.”
Kelly sees communication as the missing element in the industry’s move to DfMA. “Across much of construction there is a lack of consistency and transparency of data exchanges, and that means collaboration is hampered,” he said. “Without collaboration, innovation suffers and that impacts the industry.”
BuildingSMART International is creating hundreds of “apps for building,” which define standards and best practices at all stages of design and construction. The apps work within an “openBIM™” (building information model) structure where all project data is available to every stakeholder, without silos of hidden or “dark” data. This unites all stakeholders in one collaborative space where cost, performance and risk decisions are based on accurate, timely data, shared knowledge and best practices.
The UK Green Building Council, which promotes sustainable building practices, recently issued a report on the industry’s massive environmental impact. “Buildings account for around 35% of global resources and nearly 40% of energy use and carbon emissions,” the report noted.
Companies intent on reversing this negative tide of resource consumption include Paris-based real estate developer Woodeum. The company deploys DfMA to build from the industry’s only renewable product: wood. Specifically, a manufactured wood product known as Cross Laminated Timber (CLT) panels, which measure 185 millimeters (7.2 inches) thick and 16x3 meters (52x9.8 feet) long..
Comparatively light in weight, CLT panels have predictable material and strength characteristics and extremely good insulating qualities. Woodeum currently has more than 1,000 CLT housing units, a 125,000-square-meter office campus and a 17-story apartment block underway. Its use of DfMA allows the company to produce high-quality buildings while maximizing environmental sustainability.
PRECISION PROCESSES AND A PERFECT-FIT
“CLT elements are manufactured in the factory and assembled on site. It’s like building with LEGO,” said Woodeum architect Arnaud Heckly.
“These processes rely on precision,” added Guillaume Wiel, a wood construction engineer at Woodeum. “Our manufacturing partners provide us with panels, from which we cut out what we need with absolute accuracy.”
Collaborating around 3D digital designs simplifies complexity and allows factory-cut pieces to exactly replicate their digitally designed counterparts. When the parts arrive on site, Heckly said, “they fit perfectly.”
The company uses computer-driven milling machines and robots to produce components, just as manufacturing plants do. The result: predictable, perfectly fitting parts.
“A plumber using an architect’s 2D drawing can draw a line and say, ‘the network runs here,’” Heckly said, explaining why DfMA is superior to traditional construction techniques. “But, in reality, the plumbing passes through walls and ceilings which cannot be seen until 3D simulation is deployed. That allows us to master these issues at the upstream design and manufacturing stages,” before construction begins.
DfMA also helps to reduce the waste that runs rampant on traditional construction sites. According to the European Commission, “construction waste accounts for approximately 25%-30% of all waste generated in the EU.” When Woodeum builds, however, DfMA virtually eliminates onsite waste because every component is pre-engineered to fit.
“We try to use the scraps that are generated when cutting openings or re-using a door to build the staircase of a duplex or to make the structure of a balcony,” Wiel said. “And wood is good for the environment because it stores carbon and can easily be recycled.” Woodeum construction sites are also quiet, with fewer deliveries and “screwdrivers instead of hammers.”
PROFITING FROM DfMA
Waste and rework cut into the profitability of many construction-industry players.
“Low-margin businesses can work, but not by continuously starting from scratch every time they produce something,” said Mark Hansford, editor of industry publication New Civil Engineer. “The car industry does not work like that, and neither do other manufacturing industries. They employ factory thinking, and it is time that it well and truly arrived for construction.”
By adapting manufacturing’s proven DfMA methodologies to their industry, innovative construction enterprises are achieving efficiency, quality, cost and safety benefits that were not previously possible.
Millard’s vision for “a seamlessly digitalized, reconfigured, advanced and progressive industry” may have a long way to go for the industry as a whole, but some individual players are turning that dream into everyday reality.
How to achieve the progress is no secret, Millard said. “Just look at any successful car company.”