Single-Minute Exchange of Die · changeovers in under 10 minutes
What SMED is
SMED (Single-Minute Exchange of Die) is a way to cut the cost and waste of changing over and retooling equipment. The goal: a changeover in under 10 minutes (single-digit minutes).
The key principle — separate internal and external tasks
🔴
INTERNAL tasks
Can be done only while the equipment is stopped
MACHINE OFF!
🟢
EXTERNAL tasks
Can be done before or after the equipment stops
While the machine runs ✓
The key to SMED: move as many tasks as possible from “internal” to “external” — do the preparation WHILE the machine is still running. That is where the main gain comes from.
6 steps of a SMED analysis
1
Analyze and video the current process
Film the ENTIRE changeover as it is. No video, nothing to analyze
2
Time every task
The time of every operator action. Where does most of the time go? Where is the downtime? Where is the waiting?
3
Split tasks into internal and external
Classify every task: can it be done BEFORE or AFTER the stop?
4
Convert internal tasks to external ⭐
The key step! What prep can be done in advance? Tools? Materials? Settings?
5
Streamline and run in parallel
Which tasks can be done at the same time? Where do you need 2 operators instead of one?
6
Train the staff and roll out the standard
An SOP for the new process. Operator training. Measure the time afterward. Kaizen star
Formula 1 — the best SMED example in the world
“The best example of SMED is an F1 pit stop. Four tires changed in about 2 seconds — SMED in action!”
EXTERNAL TASKS
Getting ready for the stop
Tools ready, crew in position, tires warmed — ALL BEFORE the car stops
PARALLEL WORK
20+ mechanics at once
Everyone knows their role. Four wheels — four crews. At the same time, not one after another
STANDARDIZATION
An SOP for everyone
Every mechanic knows exactly what to do and in how many seconds. No improvising
RESULT
About 2 seconds (Red Bull record)
In the 1950s a pit stop took 60+ seconds. SMED cut the time roughly 30-fold
Illustrative case: preparing in advance (before/after)
BEFORE SMED
✗The operator waits for the machine to stop
✗Goes off to find tools and molds
✗Prepares the die set and pallet jack during downtime
✗The equipment sits idle for 40 minutes
AFTER SMED
✓The operator arrives before the stop
✓Molds and die set are ready IN ADVANCE
✓Pallet jack and wrenches are in place before the stop
✓Downtime cut to 15 minutes
Result: changeover time cut by −62%. No new equipment — just better organization.
Shigeo Shingo — the man who turned changeover into an art
1
1950s
Mazda and Shingo’s first insight
Shigeo Shingo, a consultant engineer associated with the Toyota Production System, watched a changeover at a Mazda plant: retooling a large stamping press took hours. Managers thought this was a “natural” limit — a big machine needs time. Shingo set out to prove them wrong.
2
1969
Toyota: hours → minutes
At a Toyota plant, Shingo applied his method: he separated the tasks that could be done BEFORE the stop (external) from those that required a stop (internal). Within a few months, the changeover of a 1,000-ton press dropped from about 4 hours to 3 minutes. The plant manager couldn’t believe his eyes. SMED was born.
3
1985
The SMED book — a revolution in manufacturing
Shingo’s “A Revolution in Manufacturing: The SMED System” reaches Western readers and is translated into many languages. The West is stunned: manufacturers report changeover reductions of 50–90% without capital investment. SMED becomes a core part of Lean manufacturing.
4
Today
From F1 to pharma — SMED is everywhere
Formula 1 — a pit stop in about 2 seconds instead of 60. Pharmaceutical plants — line changeovers cut from a full shift to under an hour. Fast-food chains — switching from the breakfast to the lunch menu in minutes. The principle is the same: prepare in advance everything that can be prepared in advance.
The SMED paradox: most companies believe that shorter changeovers require expensive equipment. Shingo proved that most of the gain comes from organization, not investment.
🎯 Game — Classify the tasks: internal or external?
Changeover on a forming line (mold change). Tap a task → choose its type. External — while the machine runs | Internal — only when it’s stopped
CHANGEOVER TASKS:
🔧 Remove the old mold from the machine
📦 Bring the new mold to the line
⚙️ Install the new mold
🔬 Inspect and prepare the new mold
🗝️ Gather the wrenches and tools needed
🎛️ Set the parameters on the panel
🧹 Clear leftover product from the line
📋 Fill in the changeover form
🔴 INTERNAL only when stopped
🟢 EXTERNAL before or after the stop
🧮 SMED impact calculator
Enter changeover data before and after SMED to see the financial and production impact (illustrative figures)