Rework remains one of the industry’s most significant hidden financial burdens, impacting contractor profit margins and sustainable efforts, with avoidable errors estimated to cost around £5bn per year in the UK. Ben Wallbank, a Partnerships & Digital Construction Manager from Trimble, explores how connected, digital workflows can help stop rework in its tracks.
Rework is something of an endemic within the industry. On average, direct rework costs range from 5%-12% of a project’s total contract value. In worst cases, this figure can increase to the dizzy heights of 20%-30%. As well as significant project delays, avoidable errors are reported to cost around £5bn per year in the UK.
When it comes to likely causes, poor communication between teams and stakeholders can have a very real impact, potentially leading to quality control failures, a lack of organisation and fragmented processes. Manual workflows and paper-based checks are also susceptible to human error, leading to rework further down the line if not detected. It’s likely no surprise that the design and engineering stages are the most prone to issues, with design-related errors said to account for up to 70% of all rework.
With increasing costs, volatile interest rates and skilled labour shortages, it’s clear that rework needs to be stopped in its tracks, but how?
Connected construction = better construction
‘Connected construction’ is about more than just the buzz word. On the ground, connected workflows can be invaluable in protecting against data loss, with interoperable software helping to ensure that the flow of data between platforms is kept reliable and consistent. As well as avoiding having to duplicate work (one area where the potential for human error can creep in), this enables all teams to work from the same model and data, improving both accuracy and productivity levels.
In a practical sense, this means detailers can work off the same model as the engineer, importing the model from Tekla Structural Designer into Tekla Structures where enhanced levels of detail can be added. Data can be automatically and effortlessly transferred from the drawing office to the shop floor, with CNC files further streamlining this. A direct link to fabrication can provide visibility of whether a specific component has been cut, assembled or painted, enabling teams to move fast if a last minute design change comes in.
Last-minute design changes
This can be a magnet for human error, perhaps one of the biggest areas for rework to occur. Even with the best initial model, external factors will often force our hand, such as value engineering, supply chain volatility or client-driven scope changes. Any or all of these can trigger a domino effect of amendments. Being further along in the plan of works, the cost of rework can truly spike here.
“With design-related errors accounting for up to 70% of rework, it’s clear that this is where much of the attention needs to be paid. The use of intelligent tools and 3D visualisation mean teams can design it right the first time, eliminating rework at the source.”
Fortunately, digital solutions can once again provide the answer, with parametric capabilities enabling teams to streamline and automate change management. For example, within Tekla Structures, its inherent parametric capabilities mean that any changes will automatically be applied to all associated fabrication and general arrangement drawings, while the Batch Editor tool will automatically detect similar objects within a model and reflect the same change across all.
Build it twice
With design-related errors reportedly accounting for up to 70% of rework, it’s clear that this is where much of the attention needs to be paid. The use of intelligent tools and 3D visualisation mean teams can design it right the first time, eliminating rework at the source. Through a constructible model, you can build twice, once before you go to site within the digital environment, providing assurances that the proposed scheme is constructible in the real world.
The enhanced visualisation offered by a 3D model provides far greater insight than a 2D drawing ever could, helping teams to spot clashes and plan around bottlenecks more effectively before any equipment even reaches site. Put simply, designs that look confusing on screen will be confusing out on site, leading to setting out or installation and assembly errors. Instead, by having visibility of this early on, teams can make the necessary adjustments while rework costs remain low.
From office to field
It’s not just software platforms that can help. Digital hardware can be invaluable, provided it isn’t used in isolation. It’s all about the connectivity between software and hardware, connecting the drawing office to the site. As well as helping with setting out, increasing accuracy and reducing error, it can also be used as a means of quality control, both out on site and in the factory.
Using augmented reality, you can take your phone or tablet and view the approved 3D model overlaid on the real-world context of the structure, object or assembly. By comparing the digital with the physical, you can verify that the object has been constructed, assembled and fabricated in line with the original model dimensions.
Another change that can improve quality and reduce error is MMC, frequently trumpeted as the solution to our problems. In fact, it’s been the industry mantra for decades. In recent years, it has evolved one step further to focus on standardisation, promoting the value of a kit of parts approach or industrialised construction, with digital technology once more having an important role to play in enhancing the productivity gains.
It’s easy to see the benefits. With standardised components and repeatable templates, you can reduce the variants and increase predictability, in turn minimising risk. Unlike traditional building methods, which in essence are the creation of a series of one-off prototypes, repetition and standardisation bring increased quality and productivity gains, being quicker and easier to design, manufacture and assemble.
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