// ARTICLE SERIES · OPERATIONS SCIENCE

FACTORY
PHYSICS

Factory Physics is the scientific approach to operations management. Not another methodology — a set of physical laws that govern every factory on earth, regardless of industry, machines, or organisational culture. If you run a factory, these laws apply to you.

An article series based on Factory Physics for Managers — Hopp, Spearman, Jacobs — translated into the language of operational decision-making.

SOURCE: FACTORY PHYSICS FOR MANAGERS · HOPP, SPEARMAN, JACOBS
19×
Cycle time growth at 95% utilisation
5–20%
Of cycle time is actual value-added work
3
Buffers that absorb variability — there is no fourth
1961
Year of Kingman's equation — most factories still don't know it
// 01 · WHAT IS FACTORY PHYSICS

Laws, not opinions

Lean Manufacturing tells you what to eliminate. Factory Physics tells you why it works — and where Lean alone is not enough. That's the difference between a tool and the theory the tool is built on.

Factories have physical laws analogous to the laws of thermodynamics. You can ignore them — but you cannot break them. A manager who knows these laws makes different decisions than one operating purely on intuition and experience.

Three fundamental laws: the VUT Equation (Kingman, 1961) describes how variability and utilisation destroy flow. Little's Law ties WIP, cycle time, and throughput into a mathematical identity. The Three-Buffer Principle states that every factory absorbs variability through inventory, capacity, or time — and there is no fourth option.

CTq = V × U × T
// VUT EQUATION · KINGMAN 1961
V — Variability of demand and process
U — Utilisation: u/(1−u) — non-linear, hyperbolic
T — Effective process time (te)
As U→100%, CTq→∞. Machines are "running" — but production is waiting in queue.
// FACTORY PHYSICS · FUNDAMENTAL PRINCIPLE
"Every factory has all three buffers. The only question is which ones management chooses consciously — and which ones choose themselves."
// 02 · ARTICLE SERIES

Topics

Each article covers one chapter of Factory Physics translated into operational decision language — with examples, numbers, and concrete implications for production management.

VUT equation — cycle time vs utilisation
// 01
PUBLISHED
OPS MGT · MAY 23, 2026
Your machines running at 95%? I have bad news.

Kingman's VUT equation — why high utilisation exponentially destroys flow and how to calculate the damage before it shows up on the shop floor.

READ ARTICLE
// 02
COMING SOON
OPS MGT
Little's Law: One equation that changes everything.

WIP = CT × Throughput. The mathematical identity that explains why limiting WIP is the only path to short, predictable lead times.

IN PREPARATION
// 03
COMING SOON
OPS MGT
Three Buffers: Which one are you paying for — consciously?

Inventory, capacity, time — every factory pays for all three. A deep analysis of buffer costs and buffering strategy in operational practice.

IN PREPARATION
// 04
COMING SOON
OPS MGT
CONWIP: Kanban for complex production environments.

Constant Work-in-Process — the pull system that works where classic Kanban fails. How to control WIP at the line level, not just the workstation.

IN PREPARATION
// 05
COMING SOON
OPS MGT
Absolute Benchmarking: Stop comparing yourself to competitors.

The real benchmark is not "better than industry" — it's the best possible performance in your current environment. Factory Physics shows how to calculate it.

IN PREPARATION
// 06
COMING SOON
OPS MGT
MRP doesn't know physics. That's why your queues keep growing.

Why ERP/MRP systems systematically generate WIP overflow — and what to do when your planning system fights the laws of production instead of supporting them.

IN PREPARATION

Your factory
vs. physics

Want to see where your production stands against the laws of Factory Physics? We run a diagnostic — analysing VUT, WIP, lead time, and buffers in your specific environment.

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