Have you ever wondered why, despite your team’s immense effort, financial results seem to stagnate? The answer lies not in the volume of work, but in the physics of flow.
The Correlation Between Plossl and Poiseuille
In Supply Chain Management, an organization’s health is dictated by a fascinating correlation between George Plossl’s Law (the father of MRP) and Poiseuille’s Law (fluid dynamics). At first glance, they seem from different worlds – one from production management, the other from fluid mechanics. But if you look closely, you’ll see they speak about the same thing.
Plossl’s Axiom
“All benefits of a company are directly proportional to the speed of material and information flow.” — George Plossl
If information or goods stagnate, profit evaporates. Simple. But how do we measure this stagnation? And more importantly – why do some organizations flow smoothly while others constantly get blocked? This is where physics comes in.
The Mathematics Behind Flow
If we view the Supply Chain as a pipe through which “Value” flows, Poiseuille’s Law provides us with a framework for thinking and, implicitly, three critical lessons.
First Lesson: The Power of Information to the Fourth Power
In physics, the pipe’s radius influences flow rate to the fourth power. In Supply Chain, the “radius” is the clarity and speed of information.
If you double the accuracy of real-time data (what we call Visibility), you won’t be 2 times more efficient – but 16 times. A small investment in digitalization and eliminating information silos has an exponential impact, not linear.
Second Lesson: Viscosity Is Your Bureaucracy
A thick fluid – like honey – flows with difficulty. In organizations, viscosity is represented by cumbersome, unclear processes, internal politics and centrally imposed policies, organizational culture – or rather the lack of it – lack of trust, lack of accountability, and decisions that “look good.”
You can have the best product in the world. If internal “viscosity” is high, the flow will always be anemic. It doesn’t matter how valuable the goods are – what matters is how quickly they can pass through the system.
Third Lesson: The Pressure Error
When flow decreases, the natural instinct is to “increase pressure”: micromanagement, aggressive targets, daily follow-up meetings, escalations. It seems logical – if it’s not flowing, push harder.
But physics teaches us otherwise. If you have a narrow pipe (poor communication) and a viscous fluid (bureaucracy), increasing pressure doesn’t produce flow – it produces turbulence. People burn out, errors appear, conflicts multiply, but the value reaching the end of the pipe remains the same. Or even decreases.
Pressure without widening the pipe is wasted energy.
What Does This Mean for Supply Chain Leaders?
Your company’s health doesn’t come from how hard you “push,” but from how much you manage to:
Widen the radius
Through data transparency and open communication.
Reduce viscosity
Through process simplification and elimination of bureaucracy.
Shorten the pipe
Through reducing Lead-Time and the number of decision nodes.
In an increasingly volatile world, those who survive are not the ones who apply pressure, but those who allow value to flow without friction.
A Question for Reflection
Where do you feel the greatest “viscosity” in your current flow? In data, in processes, or in organizational culture?
In my opinion, all three are interconnected – and most of the time, culture is what determines the other two.
