Conquering Variability – a Key to Lean in Project Work (Part 1)

I love introducing lean thinking to people for the first time. It’s the reason I speak at a lot of conferences, teach a course at the University of Minnesota, and teach an Intro to Lean Construction workshop every year at the LCI congress. It’s so personally rewarding if I can help the “light come on” for even a few people in one of these sessions. I think it reminds me of my first introduction to lean where I listened to Greg Howell challenge my current thinking about project work and get me to accept that there might be a better way. It changed my life.

Often when people start to accept that there might just be a better way to complete design and construction work, they start to face internal fears and doubts. One of the strongest challenges to a shift in thinking is the argument that lean, which was born in a manufacturing environment, just is not applicable to the world of building. There are just too many unknowns, and too much uncertainty for construction to work like a Toyota assembly plant. I can see why people might think that.

Construction does indeed present a unique set of challenges and sources of variation that can affect our ability to get truly smooth workflow to take hold. For example, workers inside a Toyota assembly plant probably don’t have to deal with the blizzards and minus 20-degree weather of a Minnesota winter, or the summer thunderstorms that happen regularly in St. Louis, or the seemingly never-ending rain that hampers projects in Portland or Dublin. They also don’t have to deal with the surprise of finding unsuitable soils or an archaeological site when they break ground, or the discovery of asbestos insulation inside the walls of a remodeling project where all the hazardous materials had supposedly already been abated. Construction is full of variability that just doesn’t happen in the manufacturing environment.

While this variability can seem tricky to deal with, it is not a reason to shy away from a shift toward lean thinking. Rather, lean thinking offers some of the best tools to deal with this variability. I think of applying lean to the problem of variability in two phases. First, eliminate as much variability as you can, and second, deal with the variability that you can’t (or choose not to) eliminate.

A surprising amount of variability can be eliminated by following the cycle depicted in this image. Start by taking the variability and making it visible to the entire team. Simply knowing what to measure and making it public can begin to reduce the variability all by itself. We’ve done this with both design and construction processes, are often surprised at how quickly we can reduce the variability in time to answer RFI’s, approve submittals, and turn around design reviews by simply tracking the expected vs. the actual time. When you measure something, people realize it’s important, and start paying attention.

The second step is to put your own house in order. Stop complaining about the subcontractors, the architect, the engineer, the owner, and the general contractor, and just take care of the work that you can directly impact. A little effort to control variability in the processes that you own, can go a long way in improving the flow of the work. Once you do that, you will find that your “circle of influence” over others on the project begins to expand. Your new credibility will allow you to engage others in reducing variability in processes that go beyond your immediate control and involve the broader team. This will allow you to uncover causes of variation further up the value chain and attack it together with the team.

We’ve seen this simple process make a huge difference in the flow of work on projects, and even eliminate sources of variability that most thought were untouchable. On one project, the team was able to reduce the amount of design change to work in process from about 60% to less than 5%.

The next part of conquering variability is about dealing with the variability to you cannot (or choose not to) eliminate. After all, you will not be able to control the weather, or uncover every possible disruption in advance. However, there is a lot you can do to increase your responsiveness to the unforeseen and build resiliency into your workflow. The specifics of dealing with the remaining variability will be addressed in my next article – look for it in next month’s Lean Construction Pulse.

For more information about conquering variability and how to put lean thinking to work in your projects, check out the book Better Building: Lean Practice for the Project-Driven Organization.

Comments

Klaus, Good points all. The focus on addressing, reducing and planning to manage variability is important and a good place to start. However, the simple fact is that application of lean has to go much further than that to generate all the value that is available from a genuine Lean transformation. Deming correctly pointed out that no individual, no matter how talented can perform any better than the inherent limitations of the production system in which they work. Therefore, simply put, we need also to consider whether the system in which we are working so hard to reduce variability is correctly designed in the first place. If we reduce the variability in a badly designed production process, we will get a better performing bad process. Doesn’t it make sense to look simultaneously at redesigning the production process to optimize the basic Lean Principles: Customer-defined value, value created by work streams (process awareness), making work streams flow smoothly, using pull to drive production, and embedding continuous improvement processes? If we rethink work process design, we likely reduce the variability automatically. In construction, the place to start is in the Concept/Validation phases, where a cross-functional team should devise and agree on a “Project Execution Strategy” that sets the project up for success by embedding as many Lean Principles as possible as early as possible. It’s great to discuss variability reduction, but essential to keep in mind the big picture if we are to achieve a genuine Lean Transformation.

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