Quantify the financial and capacity gains from reducing changeover time — compare current vs target setup, see the recovered production minutes per day, extra units, and annual revenue impact.
Enter your values on the left, then press Calculate.
Changeover cut from 95 to 35 minutes, 3 times per shift, £4.50 margin per unit. Enter the lab and build the financial case for the project.
Use the calculator above to quantify the financial and capacity gains from reducing changeover time. SMED turns lost setup minutes into extra production hours — the calculator translates a target changeover time into recovered minutes per day, extra units, and annual revenue impact.
SMED — Single-Minute Exchange of Die — is the Lean discipline of reducing setup and changeover time to under ten minutes. Every minute removed from a changeover that happens multiple times per day adds directly to available production time, without any extra equipment or labour spend.
Time Saved per Day = (Current Changeover Time − Target Changeover Time) × Changeovers per Day. Extra Units = Time Saved ÷ Cycle Time. Annual Revenue Impact = Extra Units × Working Days × Unit Margin. The calculator combines these to size the prize and justify the SMED programme.
A line runs four changeovers a day, each taking 45 minutes. A SMED programme targets 15 minutes. Time saved = (45 − 15) × 4 = 120 minutes per day. At a cycle time of 2 minutes, that’s 60 extra units per day with zero capital spend.
Across 250 working days at £15 margin per unit, the SMED programme delivers £225,000 of additional contribution annually — usually for the cost of a couple of kaizen workshops, some quick-release fixtures and a checklist.
SMED converts existing equipment into more capacity by removing wasted setup minutes. It enables smaller batch sizes (which improves PCE and lead time) and makes mixed-model production economically viable.
Use SMED ROI to size the prize before launching a changeover-reduction programme, to justify quick-release fixtures or pre-staging trolleys, and to track financial impact after each kaizen event.
SMED is the single most-cited capacity unlock in Lean. By collapsing setup time it makes Just-in-Time, single-piece flow and economic small batches achievable on equipment that previously required long runs.
Film a current changeover. Separate every step into internal (stopped) and external (running). Convert as much internal to external as possible, then attack the residual internal time. Re-run the calculator after each round to track the financial gain.
Pair SMED with OEE measurement and constraint analysis. The resources below help turn the financial case into a sustained changeover programme.
Single-Minute Exchange of Die — the Lean discipline of reducing equipment changeover time to under ten minutes (i.e. a single-digit number of minutes).
Time saved per day = (current − target setup time) × changeovers per day. Multiply by cycle time, working days and unit margin to get annual contribution recovered.
It enables small batch sizes economically. Without short changeovers, batch sizes have to be large to amortise setup cost — which drives lead time up and PCE down.
Internal time happens while the machine is stopped; external time happens while it is running. Most SMED gains come from converting internal activities into external ones (e.g. pre-staging tools while production continues).
Almost always, because the only spend is workshop time and minor fixturing. The recovered capacity is essentially free — provided real demand exists to absorb it.
Want to understand how SMED fits into a full changeover reduction programme? The Lean Practitioner course covers this in full.
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