There’s been a lot of buzz around the concept of “lean construction” the last couple of years, and some confusion about what it is and when it should be deployed. In reality, it’s a practical approach to construct faster, for less cost, AND at higher quality, together, without sacrificing any one of those three factors.
Why Did Lean Construction Become a Thing?
It arose in the early 90s when quality issues, increasing litigation and the problem of waste came to a head. It was clear to several industry experts that most of the issues could be dealt with through “active management of variability, starting with the structuring of the project (temporary production system) and continuing through its operation and improvement.”
In the year 2000, one of these experts, Lauri Koskela, argued for the use of the manufacturing model for construction, as observed in the hyper-efficient Toyota Production System. Further re-evaluation was done to improve construction management practices, as well as, interestingly, the use of chaos and complex systems theory, to eventually arrive at the principles of what become Lean Construction.
So there’s a lot more to lean than mere buzz. The promises of lean are great: significant project delivery advantages: reducing rework, RFIs, change orders, and wasted crew time, for a start. The practice has become more mainstream because it's been successful. In fact, the use of lean principles is sometimes mandated by owners and general contractors.
Reducing Waste is Key to Lean
The issue with lean is that too often, GCs perceive that what they have to do to truly embrace lean construction is too daunting to take on, imagining that embracing it would mean a complete overhaul of processes and teams.
Don’t worry, it’s not anywhere near that involved! In fact, you’re probably using some lean principles already whether you’re aware of it or not.
What’s key to the principle of lean is reducing waste, and chances are that’s already on your to-do list.
In order to make lean work for your projects, you’ll need to start by understanding the root causes of waste, and how each of them creates a domino effect throughout the process. Once you see how the dominoes fall, you can implement tools and processes to avoid them from the start. Soon, you’ll be enjoying more profitable projects with fewer hassles.
The causes of waste can be viewed as 16 dominoes, each of which impacts the domino that follows. They can be divided into three categories, based on where they occur during the project lifecycle: Design, Construction, and Ownership/Completion.
Let’s take a look.
"The construction industry really is setting up dominoes of waste."
The 6 Dominoes of Design Failure
The roots of waste begin during the design phase with:
- Inaccuracies in existing 2D representations
- Owner’s lack of understanding
- Incomplete coordination
- Incomplete review and approval
- Bids based on flawed drawings
- Time and cost sink due to trade findings
When existing conditions are inaccurate in the existing 2D representations, design flaws are bound to occur. Next, the owner ends up “buying off” on the scope of a project they don’t fully understand, due to the nature of 2D representation. Designers then produce deliverables with unfinished coordination, and errors and omissions, and the trades submit fixed bid prices based on those flawed documents.
Knowing there will be flaws in the design, trade contractors either build excess into their price to cover fixes, or they demand more money along the way.
On a typical project, overcoming design gaps or flaws are typically handled via RFIs–requests for information. As workers in the field uncover the various inaccuracies, unfinished details, and flaws in the design, they issue RFIs. Then they wait. This causes project disruption, delays and potential change orders leading to cost overruns.
How BIM 360 Helps
BIM 360 Docs and BIM 360 Glue make all project information and drawings, whether 3D or 2D respectively, available in real-time to stakeholders. What makes these tools so helpful is that working in 3D allows contractors access to a level of detail, including the geometry of the structure, piping, ductwork, cable tray, etc that two-dimensional drawings completely lack. However, if you’re working with an owner that prefers to view documents in 2D, these tools will also allow you to “compress” (slice) your 3D drawings into 2D if you need.
Additionally, cloud-based design tools like BIM 360 Team and Collaboration for Revit enable real-time collaboration across design stakeholders to help in the delivery of more complete, accurate drawings to construction teams.
Using these tools also enables teams to spot clashes that often would go unnoticed until well into the build phase, when correcting such mistakes becomes much more costly. Using BIM 360 Glue and BIM 360 Docs, teams can identify and resolve clashes virtually, sometimes in spending only 20 minutes in the 3D model.
Getting it right the first time prevents a lot of effort, material, time, and money from being wasted.
The 6 Dominoes of Construction Failure
The construction phase of the project presents the vulnerability to six new dominoes. If the dominoes have already fallen during the design phase, these will likely be knocked over as well.
- Requests for Information
- Change orders
- Rework and low productivity
- Delays and schedule failures or expensive and risky overtime
- Low confidence in the stability of the geometry inhibiting prefabrication
- Quality and safety problems
Dominoes that fall during the design phase can be annoying, but during construction is when they start to get crazy expensive. Every RFI costs about $1000 to $1500 apiece. Most GCs accept this cost as a given, but should you? RFIs account for about 1% of the total project budget–1% some of which could enhance your net profit.
Of course, every budget has a contingency for changes, usually between 5% and 18%, but the truth is that a significant fraction of those changes are simply the result of dominoes falling that didn’t need to fall. In other words, they could have been prevented with the proper tools and preparation.
Furthermore, RFIs are frustrating for the trades. Change orders create a chaotic environment, wreaking havoc on schedules and logistics, as trades and contractors scramble to accommodate yet another request. This leads to further mistakes, rework, low productivity and, ultimately, project delays. Owners can get frustrated with the GC for the cost overruns and delays, because they don’t realize just how much work is involved in moving crews and equipment from one location to another, or delaying a trade by a day or two.
In such a chaotic and constantly changing environment, it becomes risky to rely on prefabrication. Prefabrication can provide significant cost and time savings, but when the geometry of the project is unstable, it’s not worth the risk of creating pieces that won’t work in the real world.
Following on all the delays and rework, most projects enter an accelerated construction phase, in a desperate attempt to avoid penalties associated with missed deadlines. Costs go up due to overtime, and productivity goes down. The workforce becomes tired and sloppy. Quality declines and, even worse, safety decreases. Injuries and quality failures increase, putting a further strain on everyone involved.
Change orders and contingencies eat up huge amounts of time. Even a well-designed project that avoids the worst of the design dominoes will have some change orders, and these take more time than they should due to communication delays. Each one causes project schedule issues which can be difficult and complicated to manage effectively.
How BIM 360 Helps
BIM 360 Docs enables stakeholder collaboration from the earliest stages of construction through completion. Real-time information exchange reduces the amount of time from discovery of an issue to its resolution. The tool also connects the field to the back office, where issues and RFIs are documented, though if you’re using these tools, the number of RFIs will go down!
BIM 360 Plan makes short-term production planning easy and automatically accounts for real-time schedule adjustments.
Additionally, BIM 360 Field and BIM 360 Glue can help ensure quality in the field, with the ability to conduct virtual constructability reviews, for example. Identifying quality issues before constructing saves a tremendous amount of time and money, as they can be addressed before they have the chance to grow into much bigger problems.
The 4 Dominoes of Disappointment
Once the first few dominoes start to fall, the result is usually disappointment. This plays out as four final dominoes fall:
- Cost overruns and late completion
- Blaming other stakeholders
- Paying attorneys and accepting reduced profits
As costs begin to overrun the contingency and the project extends past its planned completion date, the blame game begins. The GC blames the trades or the owner, the owner blames the GC, the trades blame the designers, and the next stop is litigation. Litigation can take years, meanwhile shredding profits from successful projects.
On the typical project, there are so many dominoes lined up and ready to fall, that it’s impossible to know who is to blame for which problems and how much. Finger pointing and litigation is the natural result.
How BIM 360 Helps
BIM 360 Docs provides a single source of truth for all project information, via a common data environment. Every project has a detailed activity log of all project documents, drawings, versions, issues, and RFIs. It’s easy to see at a glance when problems and delays occur, and to identify who is responsible for the remedy, every step of the way.
The rich data available in the BIM 360 family of apps also makes handover easier, since the owner has all the data (in 3D) of what went into constructing the building.
Putting it all together
Throughout the project stages, there are plenty of opportunities to prevent missteps and inaccuracies that lead to waste; the key is to identify them before they manifest as problems. Fixing things virtually instead of physically during design, or identifying them as problems in the field but before they are constructed also can reduce waste and RFIs, not to mention bolster the contractor-owner relationship due to the trust it can foster.
The changes proposed here involve embracing easy-to-use BIM 360 tools as well as a proactive mindset. This is the essence of lean construction, and by no means the overhaul of construction processes that some GCs fear.
Working this way means that problems can be identified early and team members can readily collaborate on complete and accurate designs, so that projects can proceed with fewer RFIs and change orders. That means less wasted time, materials and money.
Using the power of the BIM 360 family of apps, and in particular, BIM 360 Docs, to manage your projects from start to finish, you’ll eliminate the root causes of waste early, and prevent the domino effect of waste from getting started.
Reducing waste starts with reducing paper.
Identify and reduce waste before it causes delays and rework.
Reduce Waste with BIM 360 Docs