Lean Construction Explained in (Very) Simple Words

Lean Construction Explained in (Very) Simple Words

Did you ever have to redo the same construction work twice – for free – because a client changed his mind? Ever seen windows in the wrong position? Or ordered twice as much isolation materials due to a misunderstanding?

Then the principles behind “Lean Construction” might be something for you.

Lean Construction is a construction industry methodology that’s set to shake up your project management forever – and in a good way!

What is Lean?

I’m sure that you have experienced already many smaller and bigger inefficiencies during a construction project. Things that could (and should) have gone right, but just went wrong. Sometimes the outcome is a little bit of frustration in the team, other times however, the outcome is a huge loss instead of a profit on the whole project.

Afterwards, looking back at what happened exactly, most of the times it was rather easy to avoid those (costly) mistakes. A phone call asking double confirmation of what you assumed, pictures clarifying and issue (instead of only text), or more regular site visits and field reports, and stepwise validation with the client can make a huge difference.

Lean is a framework for doing (construction) business better. It involves a number of guiding principles for construction project management that are designed to:

  • lower the overall project cost (aka more profit)
  • give a better quality outcome (aka more value, happier clients)

While there are various tools that can help a construction project be a lean construction project, the tools themselves are simply ways to implement the lean principles. It’s a theory about the way construction project management is run that leads to better project outcomes.

Lean construction mainly focusses on:

  • Reducing waste across the project
  • Improving communication across all levels of business

The principles of Lean grew out of a new way of managing the production process over at Toyota in Japan, between 1945 and 1975. It wasn’t until some years later, in the 1980’s, that the now-used term for the management and work-flow style was coined – Lean.

Although it has its roots in the manufacturing/production sector, the principles of Lean can be applied to pretty much any other industry. The framework has gained a lot of traction in the fields of both construction and software development, respectively.

A small word about software development

Duh… but this blog is supposed to be about construction business?

I know, but read on please.

As you might know, we (the authors of this blog) are software builders. And at its essence, “building software” is like… well, like “building buildings“.

This is what used to be a typical software development project several years ago:

  • Client had more or less an idea of what software they wanted
  • Obviously, they wanted a quote for the project
  • As good as possible, given the input from the client, a quote was provided by the developers
  • Based on the (often limited and incomplete) input from the client, the software was built. There was no specific focus on communication during the development.
  • At the end of the development phase, lets say 6 months later, the software was “done” and was presented to the client
  • The client says this is not what he asked for (or what he ment), asks for tons of “small” changes that “should not be that difficult, right?“, and refuses to pay the invoices.
  • You say everything is build following the original specifications and input he gave (and on which you gave your quote), and you ask the client to pay the invoice.

Does this sound familiar somehow?

Well, luckily, the software world has changed. “Agile software development” (which is the equivalent of “lean construction”) assumes that neither the client, neither the developer knows exactly upfront how the project will evolve. Also, the world is not perfect and not predicable, so things that nobody even thought of might happen during the project. There is room for change in direction built in into the way how projects are done. For that reason, there is much more focus on constant communication and interaction during the project. This allows the project to change direction even during the developments. An upfront quote is not provided. Instead, the project goes typically like this:

  • Client and developer both realise that constant alignment, communication and interaction is needed, in order to allow the project to change (slighly) direction if needed.
  • Client provides first high level input, without trying to specify all details about the project (since this is impossible).
  • Developer provides a very rough estimate of the total cost, but this is only for information of the client. The real cost will evolve during the project, together with the clients desires an wishes, which are constantly aligned on during development.
  • Developer builds a first mini prototype which is far from done and very likely full of bugs, but shows his first prototype anyhow after the first week to the client in order to get early feedback.
  • Based on the first screens of the software and how it works, client gets a better idea of what they really want, and after alignment, priorities for the next week are set.
  • Developer proceeds for another week, and makes sure to constantly validate and align with the client, in order to make sure that the software evolves in the right direction. Client also has a constant view on the total cost.
  • Software development evolves in the right direction.
  • Client is happy, since constantly involved in all small decisions that had to be taken during the development. Developer is happy since he is sure that what he is building is what the clients really wants, thanks to constant alignment.

I guess you already feel the huge value of such an agile or lean way of managing project. Less misunderstandings, less mistakes, less surprises, less needless work, less redo, less total project cost, less frustration. More profit, more value, better screens, better outcome, better translation of what the client really needs into real working software.

Everyone happy :-)

lean construction everyone happy

Now, lets see how this applies to construction.

The traditional approach to construction

With a traditional approach to a construction project, and management, we tend to plan heavily in the initial phases of the project, and try to build in as much risk management as possible.

With the traditional approach, we have four distinct, linear, project phases: initiation, development, execution of the plan, and then project completion. Because we need to complete each phase before moving on to the next – and we can’t go backwards – this rigid structure leads to inefficiencies, weak spots, and communication breakdowns.

What if the client suddenly realises he forgot to mention those small windows in the entrance hall? What if you discover old foundations deep in the ground during the excavation work that nobody was aware of? What if the government changes their policy on how buildings should be isolated?

There is little room for adaptions during the construction project, since there is more focus on the initial and upfront preparation. But once each phase is done, everything is set in stone for the next phases. This is not what we want in a rapidly changing world.

What is waste?

Waste is when there is no added value in the activity or process being performed. Waste – as quoted by Ohno, one of the founders of the Toyota system – is “anything other than the minimum amount of equipment, materials, parts, and working time absolutely essential to production.”

Let’s say, for instance, that you want to drive from A to B in the fastest time possible, while still keeping within the law. In this case, breaking on orange lights, or going even a couple of kilometers under the speed limit, and would both classify as waste.

If you dig a hole and then refill it, your outcome is zero, but you definitely spent some energy. This energy is wasted.

More waste means more people, more materials, more time, for the same output. Waste “eats” your profit margins. The more waste, the less profit and the more frustration. Too much waste can result in loss on the project.

Lean construction tries to minimise waste.

Where do we find waste in construction management?

Lean hones in on identifying the key areas in a construction project where wastage occur. These are the seven areas where waste can be identified:

1. Transport/Logistics

When transport routes and timing aren’t optimised, the movement of product isn’t optimised, and it leads to waste of resources. This will happen if materials show up before they are needed and are then required to be moved (from the spot where they arrived) to be used.

If you’ve had an early delivery of concrete bags showing up a week before they are needed, and then they need to be shuffled about the site several times to make room for other activities before they are used, then this is a clear example of transport waste. Your client isn’t going to pay you for moving those bags around!

If materials arrive just when they need to be used, then transport waste will not occur. Changes can be implemented by using clear communication with transport contractors, choosing reliable transport contractors to begin with, and site layouts that facilitate materials storage next to the spot of use.

2. Inventory/Queue

The traditional approach to materials management involves having an oversupply of materials on hand (and in the production queue) like ordering more than you need from suppliers who are often short stocked, or buying excess quantities to get a good discount.

Having excess quantities of materials on hand without good reason means that you’re wasting money storing them, or wasting them when you’ve got them left over at the end of a job.

Only asking for materials just before they are needed eliminates this waste. You’ll need to find trustworthy suppliers who are able to deliver this.

There’s also an administrative aspect to the Inventory/Queue waste area, which can include issues like having a backlog of documents waiting for approval.

3. Motion

When the movement of people isn’t optimised, then, like the transportation of materials, it creates waste. When, for example, someone on site needs to return to the office to have a meeting – that’s motion waste. If you need to visit the hardware store to pick up a missing item – that’s motion waste.

When people are moving – and they don’t have to be – they’re taking up time that is better spent on value-added tasks.

To reduce this waste, you can do things like ensuring people have all the tools and materials they need to do a job available right next to them, and using Skype meetings instead.

4. Waiting

We’ve all been on the receiving end of waiting waste – most of us several times per day! Perhaps waiting for an activity to finish that’s running late (e.g. installing floors) before we start on a new activity (polishing floors). Waiting for latecomers to arrive at a meeting. Waiting in traffic jam. Auw!

We can target waiting waste by using “pulling” whereby when the task is almost finished, we “pull” on the next team to come in, rather than them being scheduled in already and having to wait around. For latecomers, we can simply start, or add them to the communication on the phone, or via an app.

Sometimes waiting is inevitable. I personally always have something with me to read or to do. Today’s smartphones are no excuse. Your train is 30 minutes late? Read some blogposts, answer some emails, or read a book on getting things done for example.

5. Overprocessing

Overprocessing is the waste created by doing more steps in a process than is necessary for it to be “complete”. This includes things like distributing both a hard copy and an email of a particular report, polishing floors that are to be carpeted anyway, or adding some extra layers of concrete that was not needed.

To address overprocessing, make sure that you have solid systems in place where you don’t need to build in extra redundancies, and ensure that your construction works are only addressing what the customer wants. A phone call to ask double confirmation could save you days of needless work!

6. Overproduction

Linked heavily to inventory waste, overproduction is when you produce more of any given material “just in case” something goes wrong. This can occur when you’re producing more paperwork than is necessary (is anyone going to ever refer to that document again?), or you order too many doors made “just in case” of defects.

You only need as much of any one thing as is necessary (the client won’t pay the surplus anyhow) – anything over is a waste. Think carefully about your administrative overheads and what is waste in the paperwork, and consider a more reliable supplier to source your materials from so instead of “just in case”, you’ll have the right amount “just in time”.

7. Defects/Rework

When something goes wrong – either with construction, with planning, or with people – then redoing the exercise over takes time and money. This is defects/rework waste.

And it the waste hits twice as hard in this case:

  • you originally did work (example: build a wall = waste)
  • you have to undo that work (example: destroy the wall and clean up, restore ground in original condition = waste)
  • you have to do the work again (example: build the wall in the right location)

An example is having to reschedule a meeting because the customer winds up stuck in traffic, another might be if a contractor has painted the walls blue instead of green. Auch!

To eliminate this sort of waste we need to have very clear communication with plans and teams, and in the case of rescheduling meetings, perhaps alternative means of meeting communication.

Try to use todays communication methods, in a smart way to improve communication in order to avoid rework waste. Skype, Google Drive, ArchiSnapper (yep, that’s our app for field reports), Messenger, Dropbox, Evernote, … you name it.


Some also single out unused human capital as an eighth area of waste. This can be thought of as when staff on the ground have brilliant ideas for other departments, but don’t get the chance to communicate them, or when people may be able to learn a potentially useful idea or skill from someone else involved with the project, but never get the chance to interact with them.

Generally, you have the project owner, the principal architect, and the construction manager, each with teams and sub teams beneath them. There is fluid dialogue between the principal architect and the owner, and fluid dialogue between the owner and the construction manager. Each of these people should also be adept at communicating with their respective sub team leads.

However, there’s a disconnect in communication beyond these established channels, and there is a lot of room for miscommunication errors over multiple links in the communication chain, with a trickle down (and trickle up) effect.

Communication and Trust

You will notice that for many of the waste categories, you need to work with other teams that you inherently trust and can rely on. While working with these sort of teams may incur a bigger price tag in your hourly or contracted rate, you are paying for that trust that they can deliver what they promise.

It is actually more expensive going with a cheaper team or contractor who is not a good communicator and who you can not rely on. Trust is built on superior communication – a key concept in the Lean approach.

Involving all sub-teams early on in the complete construction management process, and having their ideas heard avoids costly mistakes and waste down the line. Each team is then accountable should anything go wrong in their area – they aren’t able to blame things on other teams. Involving some blue collar workers when ideas are still discussed might result in a much cheaper overall project. They could come up with very to the point hands on ideas on how to lower the risk, difficulty and cost of the overall project.

Lean focuses on collaboration and learning from one another, instead of separate business areas who don’t talk much to each other and “throw tasks and todo lists over the wall” to the next team.

The toolset you can Lean on

Lean is nothing without the correct tools in place to make it happen. Here’s some tools that are focused on the Lean approach:

  • BIM modelling tools, such as BIM 360 – a must for Lean collaboration and understanding across teams
  • ArchiSnapper – easy daily reporting, punch lists, and communication for all teams
  • Collaborative space apps such as Slack
  • A Kanban tool such as Kanbanachi is a Lean fundamental
  • The Last Planner, offered by the Lean Construction Institute
  • Google Drive or Dropbox for sharing and collaborating on documents
  • … along with many more!

To wrap up this blogpost, here is a nice video explaining what Lean Construction is about.