Where lean meets the Theory of Constraints
January 28, 2021 | 10:20 am CST
Brad Cairns is the senior principal at the Center for Lean Learning and Quantum Lean. He also runs a woodworking business called Best Damn Doors in St Thomas, Ontario, Canada, where he puts lean thinking into action every day.
For anyone who is working, I think it’s probably safe to say we are always on the lookout for a book and article or even some sage words that are going to help us do our job easier, better, faster, cheaper. (And if you’re clever, in that order.)
There are so many management philosophies, I doubt we could count them all. But in our industry, two stand out: lean manufacturing (based on the Toyota Production System) and Theory of Constraints (TOC). Now, if you talk to your lean gurus they will probably say TOC is ok but all you really need is lean. And the TOC zealots say the same thing just with the words switched around.

Lean and TOC

I had been studying the Toyota Production System a.k.a. lean, for about 15 years when I discovered TOC. I absolutely fell in love with the work of Eli Goldratt, author of the book, “The Goal,” and father of TOC. I dedicated several years to learning everything I could about his work.
Now, I suspect that I’m not alone here, having a love affair with two manufacturing mistresses. but unlike in real life they actually work better when they know about each other!  
Take any manufacturing principle and trying to boil it down to one word. That would be a challenge for any of us, so fortunately our physicist friend Dr. Goldratt has done the work for us. That word is FOCUS.
That word is probably not the exciting breakthrough you were hoping for, likely because deep down you already knew it.

Focusing on focus

Let’s examine this from the lean/TOC viewpoint. What is “lean?” The definition is probably something like this: the elimination of waste through continuous improvement. And TOC? Probably: Find the bottleneck and destroy it.
A purely lean company is likely to have a great culture, engaged employees, and everybody participating in continuous improvement. I have yet to see another philosophy have such a wonderful impact on a workplace. 
A strict TOC manufacturer is focussed on exploiting the bottleneck wherever and whenever it appears. Dramatically increasing the throughput of the company. 
The downside to the lean approach is you only see a financial return when and if one of the continuous improvement efforts touches the bottleneck. This is a little known fact in the lean world. But the reality is a minute saved on a non-bottleneck operation is a mirage. And in the TOC world, they are keenly aware of this. 
The downside to the TOC approach is you may be missing out on the joy of having amazing people and a wonderful lean culture.

Two is better than one

Circling back, it’s easy to see how we can mix these two powerful concepts. If we use the five focussing steps of TOC and identify our constraint:
  • Focusing Step #1: IDENTIFY the system’s constraint.
  • Focusing Step #2: EXPLOIT the constraint.
  • Focusing Step #3: SUBORDINATE everything else to the constraint.
  • Focusing Step #4: ELEVATE the constraint.
  • Focusing Step #5: PREVENT INERTIA from becoming the constraint!
Then, we implement all of our amazing lean tools and techniques on the constraint. Talk about a powerhouse combination. 
TOC becomes the focusing mechanism for our lean activity. And by no means do we stop all of our Lean Maniacs for making improvements everywhere they go. 
We simply have to make sure that one of them is always working on the bottleneck. This keeps our workforce happy and engaged and the management satisfied because throughput is going up.  
Before you dismiss the simplicity of our word FOCUS, just think about it. What is a lean kaizen event? 
Simply put, a team of people focused on solving a specific problem. Even a daily improvement is a person or persons focused on fixing what bugs them. 
And to really appreciate focus, let’s examine the opposite word. It could be something along the lines of distracted. 
If the secret to success is focus, the first step in that direction might be to ask yourself, “What am I doing in direct contradiction to this? Am I running around all day putting out many fires? How many projects do I have on the go?” 
Perhaps you struggle delegating and your to do list just keeps getting longer. Another key indication is you simply don’t have time to slow down and make any improvements yourself. 
I don’t know many owners/managers who are not guilty of this to some degree, after all, it’s our jobs to be the impatient visionary! 
I know many very successful companies that are “lean” and I know some that are based on “TOC.” 
Anyone who has worked with us will be a bit of both. Perhaps that’s you too! Regardless of whether you’re one, the other or both, you cannot avoid bumping into the need to focus.
Where is your focus?
The key is where to focus and when, followed closely by how. If you’re the leader of an organization, should you be focused on company culture? Or growing sales? Or increasing productivity? 
The reality is, you have to do all three. But trying to accomplish that simultaneously is a recipe for disaster. Pick the one you think you most need, and focus on it. 
When you make satisfactory gains, then change gears. Here are some of my favorite books to help you with each.
  • Culture: “The Advantage: Why Organizational Health Trumps Everything Else In Business” by Patrick Lencioni 
  • Sales: “Ultimate Sales Machine” by Chet Holmes
  • Throughput: “The Goal” by Eli Goldratt and “2 Second Lean” by Paul Akers 
Here is a hot tip for all those lean/TOC maniacs who really helped me: “Think in TOC, speak in lean.” Everyone who has been trying to explain TOC to people just had an “AH HA moment,” and if that doesn’t make sense to you, I’d be happy to explain, I’m just a phone call away.
And if you would like to watch an amazing lecture on TOC from Eli Goldratt himself, check out the video below, but settle in, it’s two hours of pure gold!

Have something to say? Share your thoughts with us in the comments below.

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About the author
Brad Cairns | President/Owner/C-Level

Brad Cairns is the senior principal at Quantum Lean and is dedicated to improving the woodworking industry in North America using lean methods. He also owns Best Damn Doors, a cabinet door manufacturing business in St. Thomas, Ontario. You can reach Brad at 519-494-2883 or [email protected].