What is lean construction and how can sites benefit from it?
Have you ever visited a building site and found a crew unable to work because an earlier step hadn’t been completed? This kind of scenario costs your project money and causes further delays for subsequent teams. And it is exactly this kind of situation that lean construction concepts aim to address.
Lean construction practices have been used in the UK since the late-1990s, although they are still far from the dominant approach to building and design. This could be a missed opportunity, however, because there are several significant benefits of lean construction – with studies showing impressive improvements in delivery times, injury rates and building costs.
So, what is lean construction, and what does it look like?
Introducing lean construction concepts
At its simplest, lean construction is an approach to construction management which attempts to remove as much waste as possible from a project while still delivering an end product that meets the customer’s requirements.
Lean design and construction draw on the concept of lean manufacturing, which was developed by Japanese auto firm Toyota in the aftermath of WWII. Toyota developed a remarkably successful manufacturing process which focused exclusively on what end customers valued, then designed products which met those desires and eliminated any unnecessary waste. It has since been adopted in a wide variety of industries – from software engineering to healthcare.
A lean approach is as much about an overarching philosophy as it is about specific tools or methods. Broadly speaking, it involves the following three key ingredients:
- Focus on customer value
The goal of lean production is to find out what the customer really wants. This is about more than just the number of units in a block of flats, for instance. Instead, it is about eliciting detailed information about what the customer values. For example, in a development aimed at first time buyers, do your target customers really want balconies, or would they be just as happy with a communal roof garden?
- Eliminate activities with no value to the customer
By identifying what the customer values, you can eliminate ‘extras’ which they don’t really want or need. The architect may, for instance, wish to add a certain kind of panelling as a design signature. However, the end customer may not really value the design – in which case it should be eliminated.
- Continual improvement
This is one of the most important lean construction concepts. Throughout the project, there needs to be a near-continual feedback loop where every team is constantly communicating with others about what needs to be done. Each team’s manager needs to also focus on how their activities could be improved. This could be something as simple as investing £100 in a new tool organising unit which, over the course of a few months, saves workers hundreds of hours searching for drill bits or wire cutters.
Lean construction practices versus traditional projects
To help describe the difference between traditional processes and lean design and construction, the following table provides some examples.
|Activity||Traditional construction||Lean construction|
|Project planning||An architect and design firm create a BIM model then the construction firm’s project management team turn this into a project. They then source sub-contractors for all the different stages.||Right from the outset, key subcontractors, project managers and architects spend time together with the client identifying exactly what they need. They then collaboratively design the project.|
|Site management||Store all tools and material for the project in a central unit, where workers walk to collect drills, cement, bricks and anything else they need.||Implement a ‘just in time’ approach to building materials, so only the right amount of cement is stored on site. Do not store tools centrally, store them closest to the places they will be used.|
|Managing project stages||Each individual team focuses on doing their tasks as efficiently as possible. It might be seen as a positive that a team of masons finished their tasks early, for example.||Think of the bigger picture. An individual team finishing their tasks early suggests that there is slack in the project plan. There might be 3-4 days before the next team arrives on-site, wasting money on everything from material storage to insurance.|
Example of lean construction concepts in action
Because lean construction is less about specific activities, and more about a general approach to building, companies can make use of a wide variety of methods, tools and approaches which help reduce waste.
Here is an example of how a project could incorporate PlanRadar to become more ‘lean’:
- Traditional defect management
A site inspector walks around your project and records all snags they notice on a paper printout of the blueprint. This is then photocopied and distributed by hand to different teams. The site inspector makes one printout for the electricians, showing where there is faulty wiring, and another printout for plasterers to fix a crack in a wall. The site inspector must make sure these printouts are given to the right person and then go back later to ensure they have been fixed.
- Lean defect management
The same site inspector patrols the site making note of snags and issues. However, this time they use PlanRadar for snagging. They take smartphone photos of any issue, locate it accurately on the blueprint and send an automatic notification to the right employee to fix it. Once that worker has completed their task, they send a photo back to the site manager, confirming it has been resolved.
As this simple example shows, a lean approach to site inspection saves time, boosts efficiency and reduces waste.
Challenges of lean construction
Although there are many benefits of lean construction, it is also important to acknowledge certain challenges too:
- Requires a wholesale culture change
Focussed on continuous improvement, communication and elimination of waste, lean construction represents a very different way of doing things. This requires everyone to understand and ‘sign up’ to the concept, which can be difficult to achieve.
- Can be limiting
Lean construction concepts have been criticised for being limited and short-term in outlook. By only focussing on immediate value for the customer, it might ignore other wider social or environmental benefits that design and construction can bring.
- Communication challenges
In countries like the UK, most projects are executed by multiple teams from multiple subcontracting companies. Lean approaches emphasise clear and continuous communication between all actors, yet this can be very difficult when there might be upwards of 20 companies involved in even a small-sized project.
Incorporating the best of lean construction practices
Lean construction practices have multiple potential benefits. However, to get the most from the concept, firms need to invest in making big changes to how they work. That kind of change can be a daunting challenge. Nonetheless, the promise of significant waste reduction and improvements in efficiency makes lean construction a concept worth investigating.
PlanRadar was founded in 2013 and provides innovative mobile-first software solutions to the construction and real estate industries. Our app is available on all iOS, Android and Windows devices and has helped more than 7,000 customers in over 44 countries to digitise their workflow.