“Time is the enemy of quality and the friend of waste.” — Lean principle
Introduction
Back in 1950, the average time for changing tyres and refuelling was 67 seconds, something unthinkable in today’s F1 era. Now, they manage to service the car in just 3.2 seconds.” Twenty years later, that would be considered a slow stop.
Content: SMED
- What is SMED
- Why SMED is needed
- 4 Steps of SMED
- 2 Key Steps: Internal and External Setup
- Example
- Key benefits
- Present industry challenges
- Conclusion
Read More: https://bit.ly/MudaMuriMura (3M- Muda, Mura, Muri)
Read More: https://bit.ly/MUDA8Waste (Muda: 8 Wastages)
Objective
SMED is about dramatically reducing setup/changeover time, the time it takes to switch a machine or process from producing one product to another. Faster changeovers mean smaller batch sizes, less inventory, and greater flexibility.
After reading the article, you will understand the meaning of SMED, why it is important, what the different steps are, key benefits and present industry challenges.
Read More: https://bit.ly/MuraMuri (Mura and Muri)
Read More: https://youtu.be/qoAvb6HnF-A (SWOT Analysis)
Definition:
Heijunka: It is the practice of smoothing and levelling production volume and product mix over a period of time to create a steady, predictable workflow.
SMED (Single Minute Exchange of Dies): It is a Lean method used to reduce machine changeover time so that switching from one product to another takes less than 10 minutes.
Standardised Work: it is the documented best method to perform a job safely, efficiently, and consistently using the least waste.
Takt time: It is the rate at which a product must be produced to meet customer demand.
Read More: https://youtu.be/F2zVsEbbILA (DOJO Room)
Read More: https://youtu.be/2e4ubL8eHns (Kaizen)
Detailed Information
SMED stands for Single-Minute Exchange of Die, a lean manufacturing methodology developed by Shigeo Shingo at Toyota in the 1950s–70s.
Despite the name, “single-minute” doesn’t mean changeovers must take exactly one minute; it means they should take less than 10 minutes (i.e., a single-digit number of minutes).
Read more: https://youtu.be/bUGzXAQSsJU (5S)
Read More: https://youtu.be/MzzQFm9paJw (Quality Circle)
Why is SMED needed?
In a traditional setup, the thought process is that,
- Because changeovers take too long, we make large batches.
- Because we make large batches, we hold a huge inventory.
- Because we hold a huge inventory, we are slow, costly, and inflexible.
The following are the key reasons why SMED is needed
- Minimise Downtime
- Every time a machine stops for a changeover, it produces zero output (20 to 40% changeover time), but costs continue (labour, overhead, energy).
- To enable small batch production
- If changeover takes only minutes, small batches become economically viable, organisation can switch products frequently without penalty.
- To respond to the customer demand faster
- enables demand-driven manufacturing to produce what is needed, when it is needed, in the quantity needed.
- To reduce manufacturing costs
- Machine downtime, inventory, scrap, space, overtime
- To improve OEE
- A typical factory loses 15–40% of OEE to changeover-related losses.
- To remain competitive in the market
- Shift from slow, inflexible, and expensive to fast, flexible, and competitive
- To reduce operator stress and errors
- Every step is pre-planned, standardised and less fatiguing
- To support sustainability goals
- Less energy wasted, Less material scrapped, Less overproduction and Smaller carbon footprint per unit produced
SMED is needed because in today’s world, the factory that changes fastest wins, and long changeovers are the single biggest obstacle to that speed.
Read More: https://youtu.be/3aeV9N8io4A (DWM- Daily Work Management)
Read More: https://youtu.be/4ZgUCVvgsWg (Fault Tree Analysis)
The Two Key Concepts
Internal setup: tasks that can only be done while the machine is stopped (e.g., physically swapping a die or tool).
External setup: tasks that can be done while the machine is still running (e.g., pre-staging tools, pre-heating dies, gathering documents).
The Four Steps of SMED
- Observe: Document the current changeover process in detail (often by video).
- Separate: Identify which activities are internal vs. external.
- Convert: Move as many internal tasks to external as possible.
- Streamline: Optimise all remaining steps (standardise, use quick-release clamps, checklists, parallel work, etc.).
Read More: https://youtu.be/BeLWXihzdh0 (Difference Between PDCA and SDCA)
Read More: https://youtu.be/zqIQbPWlBf8 (Hoshin Kanri)
Common Pitfalls to Avoid
Even well-planned SMED events can fail to deliver lasting changes if these traps aren’t addressed:
- Not involving operators: Improvements won’t stick if the people doing the setup don’t own them.
- Skipping video analysis: Memory is unreliable. Always base discussions on facts and footage.
- Focusing only on big fixes: Small improvements often give faster ROI (Return on Investment).
- Ignoring documentation and training: Without standardisation, old habits return fast.
- Treating SMED as a one-time event: The best plants treat it as an ongoing Kaizen cycle.
Read More: https://youtu.be/jPXHLizqzM8 (Obeya Room)
Read More: https://bit.ly/3Gemba (3G: Genma, Genbutsu, Genjitsu)
Key Benefit
- Enables just-in-time (JIT) production
- Reduces downtime and waste
- Allows manufacturers to respond faster to demand changes
- Supports smaller, more frequent production runs without sacrificing efficiency
- OEE (Overall Equipment Effectiveness) is the best metric to measure SMED success; by reducing changeovers, companies reclaim lost Availability and eliminate trial-and-error adjustments that cause scrap, improving Quality.
A classic analogy is a Formula 1 pit stop, through careful preparation and parallel teamwork, what once took minutes has been reduced to under 3 seconds. SMED applies the same thinking to factory floors.
Read More: https://bit.ly/OEECalculation (What is OEE?)
Read More: https://bit.ly/PESTLEANALYSIS (What is PESTLE?)
Conclusion:
SMED relies on a culture embracing continuous improvement; a lack of engagement from upper management, production teams, or support groups can undermine efforts.
The biggest time savings don’t come from people rushing around or working harder; they come from shifting internal tasks to external ones. If every tool, part, and document is ready while the machine is still running, the time spent searching and preparing is eliminated.
SMED is not just a tool; it’s a mindset shift
The golden rule of SMED: “Never let the machine wait for the operator, let the operator wait for the machine.”
Read More: https://bit.ly/7ProblemSolvingTechnique (What is Problem Solving Technique?)
Read More: https://bit.ly/4MChanges (What is 4M change?)
Present Challenges:
SMED implementation should not be treated as a standalone initiative.
Its effectiveness and long-term sustainability depend on the simultaneous adoption of supporting Lean practices such as 5S, Kaizen, Quality Circles, Total Employee Involvement (TEI), clear identification and management of dies, process standardisation, employee training, and robust production planning.
When SMED is applied in isolation, without these foundational systems, the gains achieved in setup time reduction are often short-lived, leading to inconsistency and erosion of results over time. Only when SMED is embedded within an integrated Lean ecosystem can its benefits be sustained and continuously improved.
References:
IATF 16949
Toyota Production System
Industry Experts
This is the 249th article in my Quality Management series. Each weekend, I share practical insights designed to make your Management System journey more effective, efficient, and meaningful. If you find this useful, please share it with your colleagues as well.
As Albert Einstein wisely said, “The important thing is never to stop questioning.” So, feel free to ask anything related to today’s topic. Your questions spark learning for everyone. I will respond to every query to the best of my ability, and your personal information will always remain confidential.
Your honest feedback matters greatly. Do share your thoughts, and feel free to suggest topics you’d like me to cover in the coming weeks.