In May 2024, we celebrated the 100th anniversary of Walter A. Shewhart's creation of the first control chart–a landmark that laid the foundation for modern quality management and what we now know as Statistical Process Control (SPC).
Shewhart's insight, made while working at Bell Labs in 1924, was simple but profound: distinguish between common cause variation (routine fluctuations) and special cause variation (signals of real change). From this came the control chart–later called a Process Behavior Chart (PBC) by Dr. Donald J. Wheeler.
Now consider this: Shewhart's charts predate the Toyota Production System (TPS) by more than 25 years. TPS–and by extension, what we call Lean today–took shape after World War II, heavily influenced by the work of Dr. W. Edwards Deming, who himself was influenced by Shewhart.
This isn't just a timeline curiosity. It leads to an important question:
What If Process Behavior Charts Had Come First–in Practice, Not Just in Time?
Imagine a different timeline in which PBCs had become the foundation of performance management across industries decades ago–before the rise of Lean tools, techniques, and mindsets.
I can imagine visiting organizations and almost aways seeing a lot of PBCs on the walls. Most of the time, they are correctly built, from a technical standpoint. But they're not really being used well in the context of management and desires for improvement
Before Lean, the organizations might have struggled with systematic problem solving and improvement in two scenarios:
- Reactive improvement (when they see signals in the data/chart)
- Non-reactive systemic improvement (when there's nothing but noise present, but performance is not what it needs to be)
On the positive side, though, what if every organization had embraced understanding variation before setting targets or running kaizen events?
Would organizations have been more successful with Lean over the past 25 years or so? Would they have made more real improvements–and wasted less time overreacting to noise in their data?
I believe the answer is a resounding “yes.”
Lean Without the Whiplash
In our timeline where PBCs weren't widely adopted… too often, performance management in Lean organizations still falls into the trap of overreacting to data–using red-green dashboards, celebrating random upticks, and demanding root cause analyses for normal variation.
That isn't Lean thinking. That's chaos in disguise. The Lean problem skills (including A3, root cause analysis, and the 5 whys) are being pointed in the wrong direction.
Process Behavior Charts provide a different path: one grounded in clarity, not just activity. They teach leaders when to react–and more importantly, when not to.
“Don't waste time explaining noise in a metric. There is no simple, single root cause for noise.”
— Key Point #7, Measures of Success
This way of thinking doesn't just make charts smarter. It makes leaders smarter, too.
And daily huddles in healthcare might look like the image below, instead of grids of numbers, two-data point comparisons, and emojis.
Lean organizations would also do a better job of evaluating their improvement efforts. Instead of declaring victory after two or three “above average” data points (or making questionable before-and-after comparison based on two data points), they'd have more effective Plan Do Study Adjust cycles.
They would have made more progress in terms of improvement and business results. Perhaps fewer of them would have given up on Lean after saying, “We tried Lean and it didn't work.”
Imagine If All Organizations Managed This Way
Let me tell you a story. You might have read about it recently, but I share it again.
After visiting their off-site leadership retreat, a health system CEO told me:
“Every month, we were buried in data–and yet somehow, we were still arguing over whether there was actually a problem.”
They were chasing ghosts in the metrics. Everyone had their own interpretation of the data. Trust in the numbers–and in each other–was starting to erode.
When I introduced Process Behavior Charts to them, and they started using them, the impact was immediate. The CEO reflected:
“Before PBCs, the meetings were filled with suspicion. We didn't know if the data was real or just a blip. It was exhausting.”
That's what it feels like to manage without understanding variation.
Once they adopted PBCs, the monthly firefighting turned into focused improvement. They stopped chasing blips and started managing systems. The VP of Process Excellence said:
“Now, we spend our time improving instead of arguing about the data.”
They've come to understand the difference between “common cause” variation and “special cause” variation–otherwise described as the difference between “signal” and “noise.”
Can you imagine if every organization operated that way?
Read more about that CEO's journey:
Would We Have Seen Fewer Lean Failures?
Many Lean transformations struggle not because the tools are wrong, but because the underlying thinking hasn't shifted. If an organization doesn't understand variation, they'll still:
- React to every downtick
- Blame people for results driven by systems
- Confuse motion with progress
But with PBCs, leaders can focus on signals that truly matter. They can stop rewarding luck and punishing noise. They can stop asking, “Why did the number dip last period?” and start asking, “How do we improve the system and its general performance?”
The health system I mentioned earlier didn't just improve their metrics–they transformed their leadership culture.
“This wasn't just a charting exercise,” the CEO told me. “It's a leadership philosophy. It changed how we lead.”
A Better Lens for Lean Leadership
Imagine Lean with this foundation from the beginning:
- Respect for people? Don't blame them for small fluctuations in performance, or noise.
- Continuous improvement? Focus on meaningful signals to drive root cause analysis that's focused in the right places.
- Scientific thinking? Measure impact, not just intention. Use statistically-valid rules instead of superstitious rules of thumb.
That's what Process Behavior Charts offer. They don't replace Lean–they enable and amplify it. They turn chaotic performance conversations into constructive ones. They turn fear into focus.
It's Not Too Late
Yes, SPC existed before Lean. But in too many organizations, it was never adopted or fully embraced.
We can still course correct. We can adopt Process Behavior Charts today and shift from reactive approaches to those are are more rational. From explaining every data point to improving our systems that lead to results..
Curious where to start? I wrote Measures of Success to help leaders, teams, and entire organizations adopt this mindset–without a statistics degree. Start with just one metric. Chart it properly. Ask better questions. You'll be amazed at how quickly the culture starts to shift.
“PBC thinking has transformed how we have conversations. There's more trust, more focus, and less drama.”
— Health System CEO
If more organizations had managed this way from the start, Lean might have faced fewer stumbles and earned faster, deeper success. But it's not too late to start doing it now.
Let's stop reacting and start improving–together.
Have you tried Process Behavior Charts in your organization? What did you learn?
Please scroll down (or click) to post a comment. Connect with me on LinkedIn.
Let’s work together to build a culture of continuous improvement and psychological safety. If you're a leader looking to create lasting change—not just projects—I help organizations:
- Engage people at all levels in sustainable improvement
- Shift from fear of mistakes to learning from them
- Apply Lean thinking in practical, people-centered ways
Interested in coaching or a keynote talk? Let’s start a conversation.
