SMED: Quick Changeover & Setup Reduction
Quick answer: SMED (Single-Minute Exchange of Die) is a lean method for slashing the time it takes to change a machine or line from one product to the next. The core idea is to convert as many setup steps as possible from internal (done while the machine is stopped) to external (done while it's still running), then simplify what's left. Faster changeovers let you run smaller batches and cut inventory.
Internal vs. External Setup
- Internal setup — steps that can only be done with the machine stopped (e.g., swapping a die).
- External setup — steps that can be done while the machine is still running the previous job (e.g., staging the next tooling and materials).
Most changeover time is lost because steps that could be external are done internally — searching for tools, fetching materials, making adjustments after the fact.
The Three Steps of SMED
- Separate internal from external steps — just sorting them often cuts changeover time significantly.
- Convert internal steps to external — pre-stage tooling, pre-heat, pre-assemble, and prepare everything before the line stops.
- Streamline the remaining internal steps — quick-release clamps, standardized fittings, and eliminating adjustments.
Why It Matters
Long changeovers push plants toward big batches, which create overproduction and inventory waste. Quick changeover makes small batches economical, shortening lead time and improving flow. It also directly lifts the Availability factor in OEE.
Frequently Asked Questions
Does "single-minute" mean under one minute?
It means single-digit minutes (under 10). The goal is dramatic reduction, not literally 60 seconds.
Where do we start?
Video a real changeover, list every step, and classify each as internal or external. The conversion opportunities usually jump out immediately.
Drive Faster Changeovers with Vetted Safe
Vetted Safe's Production library covers SMED, standard work, and OEE -- assign it to operators and leads and track every completion.