Design for manufacture and assembly (DfMA) could hold the key to making the construction sector more productive and competitive, as well as achieving better economic, environmental and social outcomes from infrastructure. As the UK government’s Construction Playbook sets out its aspirations for modern methods of construction, we put the case for public investment to help DfMA become mainstream.
Design for manufacture and assembly (DfMA), together with other modern methods of construction such as offsite build, has long been talked about as a way to transform the performance of the construction sector. By predominantly focusing on process, DfMA aims to bring a manufacturing sector approach and mindset into construction, heightening efficiency and helping to achieve better infrastructure outcomes.
In contrast to the traditional approach of having a bespoke design for every asset, DfMA encourages the creation of multiple assets of similar and predictable quality, which nevertheless retain the flexibility to meet a variety of user needs. This can be done by standardising a set of core components into a ‘kit of parts’ that can be manufactured and used many times; and combining this with a set of rules and common standards for how these parts should be assembled. This type of ‘platform DfMA’ approach gives the supply chain the confidence to invest in new systems and facilities that will meet the standards. In the UK, platform DfMA is being developed for buildings such as schools, hospitals, prisons and other type of infrastructure, through the work of the Construction Innovation Hub (CIH) and Mott MacDonald is an integrator for the CIH platform-based delivery workstream.
DfMA is yet to become a mainstream approach for large scale infrastructure programmes. There are several reasons why. Since establishing and developing new standards takes time and money and requires the active involvement of suppliers, there may be limited immediate gains in terms of reduced capital cost, and hence little first mover advantage in being the first in a sector to invest in these approaches. Traditional commercial models can be seen as a barrier, as can the perception that suppliers in the market do not have proven products and solutions to support the platform approach. Yet this is a chicken-and-egg situation, as suppliers are unlikely to develop such products and solutions until they can see a line of sight to revenue in the form of client requirements.
Because of this, getting a critical mass in DfMA adoption may require government intervention – either in the form of subsidies that incentivise private investment, regulatory rules to mandate certain practices, the funding of exemplar projects to show what is possible – or perhaps some combination of these three tactics.
So what are the arguments in favour of making such an intervention?
1. Raise productivity
As governments seek economic recovery from the ravages of the COVID-19 pandemic, raising productivity will be a key concern. As the US economist Paul Krugman famously observed, “Productivity is not everything, but in the long run it is nearly everything.” In most developed countries, the construction industry lags behind other sectors in its productivity as measured by GDP per capita in the workforce.
DfMA and offsite manufacture offers the construction sector the chance to access efficiencies that are commonly associated with manufacturing and factories, such as economies of scale, workforce specialisation, repeatable processes, the optimal selection and use of materials, and continuous improvement. By increasing the value of what is produced, and reducing the time and resources required to produce it, all of these process improvements promise to raise productivity.
Mott MacDonald’s work to develop a standardised kit of parts for school buildings in New South Wales, Australia has indicated that a reduction in capital cost of up to 20% can be achieved compared to a traditional design and build methodology. In the UK, Department for Education figures show that DfMA schools provide 10% more floor area than those designed in a traditional way, using the same quantity of materials.
2. Increase the predictability of employed capital
Currently, major infrastructure projects rarely deliver on time and on budget, making it difficult to make an informed judgement about whether the capital invested in them is being well spent. A project that is fully justified at £5bn may later be considered a poor use of public money if the price tag rises to £10bn. A project hit by schedule overruns may not deliver the benefits that it was forecasted to achieve until years down the line. Poor quality projects, and a lack of integration with existing systems, can lead to heightened operational costs in the lifetime of the asset.
Standardisation of design, process and components eliminates many of these risks by making the delivery process, and the performance of the finished asset, more predictable. The result of this is better budget control for project sponsors, and a reduced need for funds to cover contingencies.
3. Produce better quality assets and better outcomes
DfMA will also raise the quality of the assets that it delivers, and therefore lead to better outcomes from those assets for society. Buildings such as schools, hospitals or housing currently differ widely in terms of their acoustics, thermal comfort, energy efficiency, spatial planning and other qualities that affect operational functionality. Standardisation not only provides better made and constructed assets, but ones where the design has been optimised to provide consistently strong performance in operation. Hence schools will provide the most appropriate environment to deliver educational outcomes, hospitals will be optimised to deliver health outcomes and housing will provide affordable, warm and secure living. The standardisation of the best solutions - where everyone receives these optimal environments to learn, recover and live - will be the greatest benefit that DfMA brings to society.
4. Develop world-beating skills, techniques and products
Digital ways of working can act as a catalyst for making DfMA a success: digital technology makes it easier for clients to present their requirements to market, and designers, contractors and suppliers can then collaborate and/or compete to develop new solutions around those requirements. As well as producing better outcomes, this process leads to the progressive development of marketable skills for these players in the industry. Furthermore, DfMA supported by digital design platforms will encourage innovations in the way infrastructure is operated and maintained (e.g. through digital twins, and digital asset management) and in delivery models (contributing to higher performing enterprises). If it is a success, desirable products – whether they are components, kits of parts, entire modular assets, or the digital tools that help create them – will be created.
These skills, techniques and products could all represent an export opportunity for a country such as the UK if it can lead the way in developing world-beating DfMA expertise. Conversely, countries that do not invest in their own capabilities may end up needing to import solutions from elsewhere in the world later, at higher cost.
5. Strengthen the construction sector’s contribution to economic growth
Infrastructure investment is expected to play an important role in the economic recovery from the COVID-19 pandemic. Yet unless the construction industry modernises its methods, this infrastructure investment will hit a supply side challenge, with the economic gains being limited by the sector’s capabilities. DfMA can give the sector greater agility and responsiveness to mobilise the delivery of large-scale social infrastructure, quicker and to a more consistent standard, and maximise the value for local and national economies and society. It is also uniquely positioned to create multifunctional, flexible spaces which make sense in an era of flexible working and social distancing.
Implementing DfMA will make some demands of infrastructure clients, who will need to be clearer in how they articulate requirements across projects and programmes and invest in digital capability. But this investment and effort will be repaid by the confidence it gives to supply chain companies of all sizes, including those with innovative solutions, to step up their own capabilities in response. The result will be a progressive improvement in the industry that will benefit everybody. Government can encourage this progression – and help it gain momentum - through incentives, through regulation, or through direct funding of exemplar projects.
6. Support a green and equitable recovery
With governments across the developed world setting themselves ambitious targets for the elimination of carbon emissions, the infrastructure sector will be required to play its part by reducing operational carbon from infrastructure and embodied carbon from new assets. DfMA can help achieve a step change on each of these aspects, by designing out waste at every stage of the project lifecycle, embedding best practice on energy and resource use into new standards, extending asset life through ease of maintenance and flexibility, and promoting continuous improvement.
With cutting carbon and saving cost closely aligned, the enhanced environmental and economic outcomes of DfMA will together boost the prospects of a ‘green recovery’.
The workforce changes associated with DfMA can also boost local economies and have positive social outcomes. The emphasis on offsite manufacture means that increasingly, jobs will be created away from construction sites in factories or manufacturing hubs. If these hubs are located in areas of deprivation, they can offer the type of employment that empowers communities: stable, reliable work that is rooted in one location, enabling individuals to build a rewarding career. Rooting these jobs in a community can help create a regional multiplier effect that means the economic benefits of these jobs can be felt more widely than would be the case for the relatively transient and insecure workforce associated with traditional construction. The export of DfMA systems and products around the world would only add to this effect, creating further opportunities and prosperity.
Analysis of DfMA used for the expansion of Heathrow Airport showed that using centralised manufacturing hubs provided an economic uplift equivalent to around 2% of contract value in the local area.
In summary, there is a strong business case for investment to make DfMA mainstream practice. But it is also the right thing to do. DfMA will help our construction sector and our infrastructure perform better, make the most of our resources, and make a solid contribution to economic recovery.