By Mungo Stacy, Head of Profession - Civil, Bridge & Ground, WSP in the UK

Designed once, deployed many times
Adopting a manufacturing approach as part of the industrialisation of the creation and upgrading of road and other transport infrastructure will mean that designs will no longer be bespoke and hand-crafted. They will be created from rule-based algorithms and a selection of optimum, pre-defined model components, which would be applied across multiple schemes.  And as with high quality manufacturing, the human input will separate the good designs from the bad. As this approach matures, it could then be organised into product families and platforms designed for efficient manufacture, transportation and installation.

To achieve the productivity improvements a manufacturing approach for the sector is expected to deliver there must be trade-offs particularly the balance between variations (customisation) and standardisation. Mass customisation may offer a compromise.  This means that for most elements of infrastructure like the component parts of a typical motorway scheme, standardisation will offer greater benefits and value. The trade off is that the design is developed around the available products, rather than developing bespoke products to fit the design. For example, the gantries on a typical motorway scheme may come in multiples of a standard length. The digital twin would support the use of standard components by helping to ensure each element will fit perfectly when assembled on site because there can be no final adjustments such as cutting to size. Use of the digital twin is likely to compliment physical prototyping with the manufacturing approach. This will enable the product to be refined based on ease of manufacture and assemble, and will also provide a teaching aid to the site assembly crews.

With fewer tasks completed on site, construction would move to a controlled, factory, environment resulting in better safety management, increased efficiencies through the use of robotics and reduced wasted through lean processes. Since each component would be deployed on multiple schemes, this approach  also provides greater potential for feedback on performance both during installation and in use. This data would allow for refinements to be made and validation that the anticipated improvements are delivered as expected. 

One trade-off with the manufacturing approach is that that design for a specific project must be fixed far earlier than with a traditional construction approach. This early design fix is essential to allow fabrication to be managed efficiently in the manufacturing environment. This approach will reduce the opportunity and flexibility for late changes to be made to the design, but will bring benefits such as greater project certainty and cost savings.

Designing products and platforms
Until now the majority of design work undertaken on a road scheme is bespoke to that particular project. In the future, more of the effort will be focussed on designing the products and platforms that road designers regularly utilise, shifting to the principle of ‘design one, use often.’

This method is already used in the automotive sector where car manufacturers have a range of models and brands marketed to different customers.  Whilst each model has its own specification and set of features, the model ranges often share a common chassis and use a standard catalogue of components. The construction sector could see time and cost benefits by applying a similar approach. The great number of the same products manufactured, the cheaper they could be. Standardisation will also reduce the time needed for installation, which in turn will minimise the impact on road users from temporary traffic management ad road closures. 

Transitioning to a manufacturing approach will require significant changes to the way infrastructure projects are planned and executed.  Engineering professionals will have an important role to play in creating a viable approach. Whilst the vision of roads rolling off a production line as easily as cars do today may be compelling, there are significant challenges to making this a reality. Road projects are tens of km in length and specific constraints such as ground conditions and adjacent land use, including residential properties, must be considered. Upgrades to existing roads add further constraints as traffic flows need to be safely maintained during the works.

Due to this complexity, all stakeholders will need to be engaged in selecting the right balance and approach to manufacturing for infrastructure projects. For example, some projects may benefit from a temporary mobile production facility close to site where final assemblies are completed and, for others it might be more efficient to transport fully assembled components directly from the factory. On long sites, the use of linear production process such as slip forming kerbs and central reserves may be appropriate.  The manufacturing approach will include all these aspects and others will combine them in the most efficient and effective way for the particular scheme, so that standardisation and production are the norm.

Adopting a manufacturing approach, underpinned by the digital twin, will bring significant changes for both the people and organisations delivering, operating and maintaining infrastructure. Suppliers such as fabricators and installers will need to be engaged earlier in the design process to leverage their specific expertise. A contractual and collaborative framework which balances the sharing of knowledge, innovation, and risk will be needed. Clients will play a pivotal role in establishing the right delivery environment. Investment across the industry to develop and attract the skills needed will be essential.

The adoption of best practice from the manufacturing sector, and the use of technologies such as the digital twin will act as a catalyst for a step change in improvement towards more efficient and safer highways – both in construction and in use. A key challenge for the next decade will be to scale these approaches and apply them effectively to the design, delivery, and management of our transport infrastructure

About Mungo Stacy
Mungo leads the technical excellence strand of WSP's strategy in the civil, bridge and ground discipline. He has responsibility for the capability and competence of over 550 engineers in the discipline. Mungo is a civil engineer with extensive experience of the design, construction, maintenance and refurbishment of a wide range of structures, both in this country and overseas, notably in Hong Kong. Follow him on LinkedIn here

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