What is an example of SMED?

A press setter who used to fetch the next die, bolts and tools after the press stopped now does it from a checklist while the old job runs, so the press stops only for the die swap, clamping and the first good part. In the illustrative press example on this page that alone takes the stop from 63 to 35 minutes, without buying anything.

What are the stages of SMED?

Shingo describes a preliminary stage, where internal and external work are mixed, and three conceptual stages: separate internal from external work, convert internal work to external, and improve every remaining step of both. Most changeovers start in the preliminary stage, so a timed study of today's changeover comes first.

What does single minute mean in SMED?

A changeover of under 10 minutes, a single-digit number of minutes. It does not mean one minute. The Lean Enterprise Institute's lexicon defines it the same way.

What is the difference between internal and external setup?

Internal setup can only be done with the machine stopped, such as swapping a die. External setup can be done while the machine runs, such as bringing the next die to the machine or putting the old one away.

Which SMED technique should you try first?

Separating internal and external work, with a checklist and everything staged at the machine before the stop. It costs little and Shingo puts it first. Spend on clamps, carts, presetters or spare plates only for the internal steps that are left.

Does a faster changeover always raise output?

Only on a machine that limits output. On a machine with spare capacity, the gain is the chance to change over more often, run smaller batches and hold less inventory. Decide what the saved minutes are for before you start.

How do you measure changeover time for SMED?

From the last good part of the old run to the first good part of the new one at normal speed, including trial parts and adjustments. Film it, then list each step with its time on a worksheet and mark it internal or external.

Example gallery · 16 examples · Value stream mapping and flow

SMED examples: 16 changeovers, before and after

SMED (single-minute exchange of die) is Shigeo Shingo's method for cutting changeover time, counted from the last good part of one product to the first good part of the next. You separate the work that needs the machine stopped (internal) from the work that can be done while it runs (external), move as much as you can outside the stop, then shorten what is left. Single minute means under 10 minutes, not one minute. The 16 worked examples below are sorted by Shingo's stages and can be filtered by technique or by machine. Each one shows the changeover before and after, what the change took, the step that is now the longest and how to keep the gain. The minutes are illustrative: round numbers built from the method to show how the arithmetic works, not results from a particular plant.

Want the long version? How to Reduce Changeover Time: SMED and Standard Work: What changeover time is, how to measure it, and three ways to cut it: SMED, documented procedures and standard work.

Each card has a before and an after timeline on the same scale. Solid navy blocks are internal work, which needs the machine stopped. Striped gold blocks are external work, which could be done while it runs; in the before timeline, striped blocks inside the stop are the first thing to move. The dashed line marks 10 minutes, the single-minute target. The numbers in the bars match the step list under each card, and every minute is illustrative.

Technique

Machine

Showing 16 of 16 examples

Stage 1: separate internal and external work

List every step and ask whether it really needs the machine stopped. Fetching, checking and putting things away do not, so they move before the stop or after the restart. It is the cheapest stage and comes first.

- Checklist
- Pre-staging
- Stamping press
Checklist and staged cart on a stamping press
The setter used to start fetching the die, bolts and paperwork after the last good part. Now a checklist is worked through while the old job runs, everything waits on a cart beside the press, and the old die goes back to the rack after the restart.
Illustrative numbersBefore: stopped 63 min, 28 min of it external work. After: stopped 35 min, plus 24 min done while running. The stop is 28 min shorter.
Step by step (7 steps)
1. 1Find the setup sheet for the next jobBefore: 4 min, stopped (external work)After: 4 min, while running
2. 2Fetch the next die from the rack by forkliftBefore: 11 min, stopped (external work)After: 11 min, while running
3. 3Look for clamps, bolts and wrenchesBefore: 7 min, stopped (external work)After: 3 min, while running
4. 4Unclamp and lift out the old dieBefore: 9 min, stoppedAfter: 9 min, stopped
5. 5Set and clamp the new dieBefore: 12 min, stoppedAfter: 12 min, stopped
6. 6Set shut height and feed, trial strokes to the first good partBefore: 14 min, stoppedAfter: 14 min, stopped
7. 7Take the old die back to the rackBefore: 6 min, stopped (external work)After: 6 min, while running
What it took:
A cart, a one-page checklist and starting the preparation about half an hour before the planned stop. No new tooling. The 24 minutes of preparation still happen, but the press runs while they do.
Longest step now:
Shut height, feed and trial strokes, 14 min. Fixed settings come next: see the standard die height example.
Keep it:
The press does not stop until the cart is checked complete. The supervisor signs the checklist at the stop, and each changeover time goes on the log, so drift shows within a week.
See also: Standard die height, no shut height adjustment, Quick clamps instead of bolts on a press
- Function check
- Pre-staging
- Injection molding
Next mold checked and parked before the stop
Faults on the incoming mold, like a leaking water fitting, used to show up only after it was hung. Now the mold is cleaned, inspected and its fittings tested at a bench while the machine runs, then parked on a cart at the press.
Illustrative numbersBefore: stopped 72 min, 14 min of it external work. After: stopped 52 min, plus 19 min done while running. The stop is 20 min shorter.
Step by step (8 steps)
1. 1Bring the next mold from the rackBefore: 8 min, stopped (external work)After: 8 min, while running
2. 2Clean the mold faces and check for damageBefore: 6 min, stopped (external work)After: 6 min, while running
3. 3Test water fittings and ejectors at the benchBefore: not done beforeAfter: 5 min, while running
4. 4Disconnect lines, unclamp and crane out the old moldBefore: 12 min, stoppedAfter: 12 min, stopped
5. 5Crane in and clamp the new moldBefore: 10 min, stoppedAfter: 10 min, stopped
6. 6Connect water and heater linesBefore: 5 min, stoppedAfter: 5 min, stopped
7. 7Replace a leaking fitting found at hookupBefore: 6 min, stoppedAfter: no longer needed
8. 8Heat, purge and trial shots to the first good partBefore: 25 min, stoppedAfter: 25 min, stopped
What it took:
A bench with water and air to test fittings, spare fittings kept there and a marked spot to park the next mold. The fitting fault is now found and fixed off the machine, before anyone waits for it.
Longest step now:
Heating, purging and trial shots, 25 min. Heating the mold off the machine is the next step: see the mold preheating example.
Keep it:
A mold is not released to the press until its bench check is signed. A failed check goes to the toolroom and the scheduler hears about it before the stop, not during it.
See also: Mold preheated off the machine, Two people in parallel on a mold change
- Checklist
- Pre-staging
- Filling and packaging
Materials, labels and change parts staged for a packing line
Materials and change parts used to be collected once the line stopped, and the line then waited for quality to come and sign the clearance. Now the next order's materials and change parts are staged on a trolley before the stop, and the checklist books the quality check for the stop time.
Illustrative numbersBefore: stopped 62 min, 18 min of it external work. After: stopped 37 min, plus 14 min done while running. The stop is 25 min shorter.
Step by step (6 steps)
1. 1Fetch cartons, labels and leaflets for the next productBefore: 10 min, stopped (external work)After: 10 min, while running
2. 2Find the change parts for the next carton sizeBefore: 8 min, stopped (external work)After: 4 min, while running
3. 3Line clearance: remove every old carton, label and leafletBefore: 8 min, stoppedAfter: 8 min, stopped
4. 4Wait for quality to check and sign the clearanceBefore: 9 min, stoppedAfter: 2 min, stopped
5. 5Swap change parts and the carton magazineBefore: 15 min, stoppedAfter: 15 min, stopped
6. 6Run up, check the first cartons and adjustBefore: 12 min, stoppedAfter: 12 min, stopped
What it took:
A trolley per carton size with its parts labelled, and one line on the checklist to call quality 15 minutes before the stop. Line clearance itself is not shortened; it stays internal and signed.
Longest step now:
Swapping change parts and the carton magazine, 15 min. See the color-coded change parts and marked rail settings examples.
Keep it:
Staging is on the shift's standard work with a time, and the trolley is checked against the order before the stop. Any wait for a signature is written on the changeover record, so it shows in the weekly review.
See also: Color-coded change parts with hand knobs, bottle labeler, Guide rails set to marked positions, case packer

Stage 2: convert internal work to external

Look again at the steps that seem to need the machine stopped and change how they are done so they no longer do: heat, preset, pre-load or set up on a spare plate off the machine, or make every die the same height.

- Prepare off the machine
- Injection molding
Mold preheated off the machine
The mold used to be heated on the press, so the machine stood idle while it warmed up and the first shots from a cold mold were scrap. Now it is heated at a staging station with its own temperature controller and arrives hot, needing only a short top-up.
Illustrative numbersBefore: stopped 59 min. After: stopped 38 min, plus 25 min done while running. The stop is 21 min shorter.
Step by step (6 steps)
1. 1Hang and clamp the moldBefore: 20 min, stoppedAfter: 20 min, stopped
2. 2Connect water and heater linesBefore: 6 min, stoppedAfter: 6 min, stopped
3. 3Heat the mold on the press to process temperatureBefore: 18 min, stoppedAfter: no longer needed
4. 4Preheat the mold at a staging stationBefore: not done beforeAfter: 25 min, while running
5. 5Top up to temperature after hookupBefore: not done beforeAfter: 4 min, stopped
6. 6Purge and trial shots until parts are in specBefore: 15 min, stoppedAfter: 8 min, stopped
What it took:
A temperature controller and hookups at the staging station, a cart that can carry a hot mold, heat-resistant gloves and a hot-surface sign. The heating takes longer than before, but the press no longer waits for it.
Longest step now:
Hanging and clamping, 20 min. See the quick clamps and two-person mold change examples.
Keep it:
The preheat start time is on the schedule, so the mold is at temperature when the press stops. Record the mold temperature at hookup; if it arrives cold, the record shows it.
See also: Two people in parallel on a mold change, Quick clamps instead of bolts on a press
- Prepare off the machine
- Intermediate jig
- SMT line
Feeders loaded on a spare trolley, SMT line
Reels used to be swapped feeder by feeder on the stopped machine. Now the next job's feeders are loaded and scan-verified on a spare trolley while the current job runs, and the changeover swaps the whole trolley.
Illustrative numbersBefore: stopped 65 min, 10 min of it external work. After: stopped 21 min, plus 47 min done while running. The stop is 44 min shorter.
Step by step (6 steps)
1. 1Pick reels for the next board from storesBefore: 10 min, stopped (external work)After: 10 min, while running
2. 2Unload the old reels from the feedersBefore: 12 min, stoppedAfter: 12 min, while running
3. 3Load and verify the new reels in the feedersBefore: 25 min, stoppedAfter: 25 min, while running
4. 4Swap the whole feeder trolleyBefore: not done beforeAfter: 3 min, stopped
5. 5Change the stencil and board support pinsBefore: 8 min, stoppedAfter: 8 min, stopped
6. 6Load the program, run and inspect the first boardBefore: 10 min, stoppedAfter: 10 min, stopped
What it took:
A second feeder trolley and enough feeders for two setups, which is capital spend, plus a place to load and verify them off the line. Loading the reels takes as long as before; it just happens while the line builds boards.
Longest step now:
Program, first board and inspection, 10 min, then the stencil and support pins. A second person on the stencil at the same time would shorten the stop again.
Keep it:
The trolley is not docked until its verification report is complete. Feeders are counted, so a missing one is found during the run, not at the stop.
See also: Fixture set up on a spare plate, CNC machining center
- Prepare off the machine
- CNC machining
Tools measured on a presetter, CNC machining center
Tool holders used to be assembled at the machine after it stopped, then every tool was touched off on the machine. Now holders are built and measured on a presetter during the previous job, and only the offsets are entered at the control.
Illustrative numbersBefore: stopped 66 min, 15 min of it external work. After: stopped 33 min, plus 25 min done while running. The stop is 33 min shorter.
Step by step (7 steps)
1. 1Assemble tool holders for the next jobBefore: 15 min, stopped (external work)After: 15 min, while running
2. 2Measure tool lengths on a presetterBefore: not done beforeAfter: 10 min, while running
3. 3Load the tools into the magazineBefore: 6 min, stoppedAfter: 6 min, stopped
4. 4Touch off each tool on the machine to set its lengthBefore: 16 min, stoppedAfter: no longer needed
5. 5Enter the tool offsets from the presetterBefore: not done beforeAfter: 3 min, stopped
6. 6Change the fixture and indicate itBefore: 14 min, stoppedAfter: 14 min, stopped
7. 7Cut the first part, measure and adjust offsetsBefore: 15 min, stoppedAfter: 10 min, stopped
What it took:
A tool presetter, which is capital spend, and a second set of holders for the tools used most. If your control can take offsets straight from the presetter, typing errors go away too.
Longest step now:
Changing and indicating the fixture, 14 min. See the spare fixture plate and fixture keys examples.
Keep it:
Offsets only come from the presetter label or transfer, never from memory. Check the first part every time; a wrong offset is the one error this change can add.
See also: Fixture set up on a spare plate, CNC machining center, Fixture keys in the table slot instead of indicating
- Intermediate jig
- CNC machining
Fixture set up on a spare plate, CNC machining center
The fixture used to be bolted to the table and indicated with the machine stopped. Now each fixture is mounted and squared on its own plate at a bench, an intermediate jig in Shingo's terms, and the plate drops onto locating pins on the table in one known position.
Illustrative numbersBefore: stopped 45 min. After: stopped 9 min, plus 18 min done while running. The stop is 36 min shorter, under the 10-minute line.
Step by step (6 steps)
1. 1Remove the old fixture from the tableBefore: 8 min, stoppedAfter: no longer needed
2. 2Release the old plate and lift it offBefore: not done beforeAfter: 2 min, stopped
3. 3Bolt the new fixture downBefore: 10 min, stoppedAfter: 10 min, while running
4. 4Indicate and square the fixtureBefore: 15 min, stoppedAfter: 8 min, while running
5. 5Lock the plate on its locating pins and call its stored work offsetBefore: not done beforeAfter: 2 min, stopped
6. 6Cut the first part, measure and adjustBefore: 12 min, stoppedAfter: 5 min, stopped
What it took:
A zero-point or pallet base on the table and one plate per fixture, which is capital spend, plus a bench with a reference surface for squaring fixtures on their plates.
Longest step now:
Cutting and measuring the first part, 5 min. At 9 minutes this changeover is single minute; keep the first-part check, it is how you know the change worked.
Keep it:
Each fixture stays on its plate between jobs and the plates live on a labelled rack. Each plate's work offset is stored under its name in the control and confirmed by the first part.
See also: Tools measured on a presetter, CNC machining center, Fixture keys in the table slot instead of indicating
- Standardized functions
- Fixed settings and stops
- Stamping press
Standard die height, no shut height adjustment
Each die used to have its own closed height, so the ram was reset at every change and then corrected by trial. Now spacer blocks bring every die that runs on this press to the same shut height, so the ram setting never changes.
Illustrative numbersBefore: stopped 45 min. After: stopped 23 min. The stop is 22 min shorter.
Step by step (4 steps)
1. 1Lift out the old dieBefore: 8 min, stoppedAfter: 8 min, stopped
2. 2Set and align the new dieBefore: 10 min, stoppedAfter: 10 min, stopped
3. 3Reset the ram shut height for the new dieBefore: 12 min, stoppedAfter: no longer needed
4. 4Trial strokes, readjust shut height until the part is goodBefore: 15 min, stoppedAfter: 5 min, stopped
What it took:
Toolroom time to fit spacer blocks to each die, and a rule that new dies are ordered at the standard height. Shingo calls this standardizing the function, not the shape: only the height that matters to the press is made the same.
Longest step now:
Setting and aligning the new die, 10 min. See the die carts example for rolling it in against fixed stops.
Keep it:
The standard shut height is written in the die specification and checked when a die comes back from repair. Blocks are fastened to the die, never stored loose.
See also: Die carts at bolster height, stamping press, Quick clamps instead of bolts on a press

Stage 3: shorten the internal work that is left

Shingo's third stage improves every remaining step. For internal work that means fasteners that need one turn or none, two people working to a written split, and fixed stops and settings that remove trial and adjustment.

- Quick-release fasteners
- Standardized functions
- Stamping press
Quick clamps instead of bolts on a press
Each die was held by eight bolts, each tightened through many turns, and bolts of the right length had to be found first. Now clamps with U-slots slide onto a clamping edge of the same thickness on every die and lock with one turn or one lever.
Illustrative numbersBefore: stopped 44 min. After: stopped 25 min. The stop is 19 min shorter.
Step by step (5 steps)
1. 1Loosen and remove eight die boltsBefore: 10 min, stoppedAfter: 2 min, stopped
2. 2Lift out the old dieBefore: 6 min, stoppedAfter: 6 min, stopped
3. 3Set the new dieBefore: 6 min, stoppedAfter: 6 min, stopped
4. 4Find bolts of the right length and tighten eight boltsBefore: 14 min, stoppedAfter: 3 min, stopped
5. 5Trial strokes to the first good partBefore: 8 min, stoppedAfter: 8 min, stopped
What it took:
Quick clamps for the press and a clamping edge machined to one thickness on every die, so one clamp fits all of them. Shingo's point is that only the last turn of a bolt tightens it; the other turns are just movement.
Longest step now:
Trial strokes, 8 min, then lifting each die. See the standard die height and die carts examples.
Keep it:
No loose die bolts are kept at the press, so nobody falls back on them. The clamps are on the daily press check, and the clamping edge thickness is in the die specification.
See also: Standard die height, no shut height adjustment, Die carts at bolster height, stamping press
- Parallel work
- Injection molding
Two people in parallel on a mold change
One setter used to do every step, walking round the press between the two sides. Now two people work to a written split: each takes one side for lines and clamps, and the second person guides the crane lift that one person used to manage alone.
Illustrative numbersBefore: stopped 74 min, 5 min of it external work. After: stopped 45 min with two people working in parallel, plus 5 min done while running. The stop is 29 min shorter.
Step by step (10 steps)
1. 1Disconnect water and heater lines, operator sideBefore: 5 min, stoppedAfter: 5 min, stopped
2. 2Walk round, disconnect lines on the far sideBefore: 7 min, stoppedAfter: 5 min, stopped, second person
3. 3Unclamp, operator sideBefore: 4 min, stoppedAfter: 4 min, stopped
4. 4Walk round, unclamp the far sideBefore: 6 min, stoppedAfter: 4 min, stopped, second person
5. 5Crane the old mold out and the new mold inBefore: 18 min, stoppedAfter: 15 min, stopped
6. 6Guide the load and keep the area clear during the liftBefore: not done beforeAfter: 15 min, stopped, second person
7. 7Clamp and connect, operator sideBefore: 6 min, stoppedAfter: 6 min, stopped
8. 8Walk round, clamp and connect the far sideBefore: 8 min, stoppedAfter: 6 min, stopped, second person
9. 9Purge and trial shots to the first good partBefore: 15 min, stoppedAfter: 15 min, stopped
10. 10Return tools and fill in the changeover recordBefore: 5 min, stopped (external work)After: 5 min, while running
What it took:
A second trained person for about 45 minutes per change. Total person-minutes go up slightly, from 74 to 80, while the stop falls from 74 to 45 minutes; that trade pays on a machine whose stopped time matters.
Longest step now:
The crane lift and the purge and trial shots, 15 min each. Preheating the mold off the machine shortens the trial shots: see the mold preheating example.
Keep it:
The split is written as a two-column sequence and trained, with agreed hand signals for the lift. Each person applies their own lock before reaching into the machine, and nobody moves the crane until both are clear.
See also: Mold preheated off the machine, Next mold checked and parked before the stop
- Fixed settings and stops
- CNC machining
Fixture keys in the table slot instead of indicating
The vise used to be indicated parallel to the axis by tapping and re-checking with a dial indicator, and the work offset was found with an edge finder. Now keys under the vise fit the table's T-slot, so it lands square, and its offset for that table position is stored.
Illustrative numbersBefore: stopped 41 min. After: stopped 22 min. The stop is 19 min shorter.
Step by step (6 steps)
1. 1Remove the old viseBefore: 6 min, stoppedAfter: 6 min, stopped
2. 2Place the new vise on the tableBefore: 4 min, stoppedAfter: 4 min, stopped
3. 3Align the vise to the machine axisBefore: 12 min, stoppedAfter: 1 min, stopped
4. 4Tighten the vise downBefore: 3 min, stoppedAfter: 3 min, stopped
5. 5Set the work offsetBefore: 8 min, stoppedAfter: 2 min, stopped
6. 6Cut the first part, measure and adjustBefore: 8 min, stoppedAfter: 6 min, stopped
What it took:
Keys fitted to the vise base, a marked position on the table for each vise and stored offsets in the control. The aim is to remove the adjustment altogether, not to do it faster.
Longest step now:
Cutting the first part and removing the old vise, 6 min each. A spare fixture plate removes both vise moves: see that example.
Keep it:
Check the keys for wear at preventive maintenance, since a worn key brings the adjustment back. Name each stored offset after its vise and table position so the right one is called.
See also: Fixture set up on a spare plate, CNC machining center
- Fixed settings and stops
- Visual markings
- Filling and packaging
Guide rails set to marked positions, case packer
Guide rails and glue guns used to be set by eye with a sample carton and a tape measure, then corrected while cases jammed. Now each hand wheel has a position counter, each carton size has its settings on a sheet at the machine, and a colored mark sits at each setting.
Illustrative numbersBefore: stopped 42 min. After: stopped 18 min. The stop is 24 min shorter.
Step by step (4 steps)
1. 1Swap the change partsBefore: 10 min, stoppedAfter: 10 min, stopped
2. 2Set the guide rail widthsBefore: 12 min, stoppedAfter: 2 min, stopped
3. 3Set the glue gun positionsBefore: 6 min, stoppedAfter: 2 min, stopped
4. 4Run cases and adjust until they stop jammingBefore: 14 min, stoppedAfter: 4 min, stopped
What it took:
Position counters on the hand wheels, one setting sheet per size and paint or label marks. Little spend; most of the work is finding and agreeing the right setting for each size once.
Longest step now:
Swapping the change parts, 10 min. See the color-coded change parts example.
Keep it:
When someone finds a better setting, they change the sheet, not just the machine. Settings are checked in the layered audit, and jams after a change are logged against the carton size.
See also: Color-coded change parts with hand knobs, bottle labeler, Materials, labels and change parts staged for a packing line
- Visual markings
- Quick-release fasteners
- Filling and packaging
Color-coded change parts with hand knobs, bottle labeler
Change parts for different bottle sizes looked alike, were held by bolts and could go on the wrong way round. Now each size has its own color, the parts lock with hand knobs, and an offset pin lets each part fit only one way.
Illustrative numbersBefore: stopped 33 min, 6 min of it external work. After: stopped 11 min, plus 2 min done while running. The stop is 22 min shorter.
Step by step (4 steps)
1. 1Find the star wheel and guides for the bottle sizeBefore: 6 min, stopped (external work)After: 2 min, while running
2. 2Remove the old parts: twelve bolts with wrenchesBefore: 9 min, stoppedAfter: 3 min, stopped
3. 3Fit the new parts, refitting any put on the wrong way roundBefore: 10 min, stoppedAfter: 4 min, stopped
4. 4Run bottles and adjustBefore: 8 min, stoppedAfter: 4 min, stopped
What it took:
Colored or marked parts for each size, hand knobs in place of bolts and an offset locating pin on each part, which is a poka-yoke as well as a time saver. A color chart at the machine shows which color goes with which size.
Longest step now:
Fitting the new parts and running up, 4 min each. At 11 minutes this is close to single minute; the run-up is next.
Keep it:
New and replacement parts are ordered in the size's color with the pin. A part found without its color goes on the maintenance board the same day.
See also: Guide rails set to marked positions, case packer

Stage 3: shorten the external work too

External work does not stop the machine, but when it is slow or late the stop starts late or waits for it. Tool storage at the machine, die carts and parts delivered in kits keep it short and on time.

- Shadow boards
- CNC machining
Shadow-boarded tool cart, CNC lathe
Tools were shared between lathes and kept in a drawer, so every change began with a search. Now the lathe has its own cart with a shadow board for its tools, gauge and setup sheet, and an empty outline shows what is missing before the stop.
Illustrative numbersBefore: stopped 44 min, 16 min of it external work. After: stopped 29 min, plus 4 min done while running. The stop is 15 min shorter.
Step by step (8 steps)
1. 1Look for the chuck key, jaw wrench and hex keysBefore: 7 min, stopped (external work)After: no longer needed
2. 2Check the cart is complete before the stopBefore: not done beforeAfter: 2 min, while running
3. 3Take the tools from the shadow board on the cartBefore: not done beforeAfter: 1 min, stopped
4. 4Change the chuck jawsBefore: 8 min, stoppedAfter: 8 min, stopped
5. 5Change the turret toolsBefore: 10 min, stoppedAfter: 10 min, stopped
6. 6Find the gauge and the setup sheetBefore: 5 min, stopped (external work)After: no longer needed
7. 7Cut the first part, measure and adjustBefore: 10 min, stoppedAfter: 10 min, stopped
8. 8Put the tools awayBefore: 4 min, stopped (external work)After: 2 min, while running
What it took:
A cart with a shadow board and a second set of the tools used most, so tools never leave this machine. The shadow board planner template helps with the layout.
Longest step now:
Changing the turret tools and cutting the first part, 10 min each. Presetting tools off the machine is next: see the tool presetter example.
Keep it:
The cart is checked at the start of every shift and before each stop. Tools are not borrowed; a missing tool gets a red tag, not a search.
See also: Tools measured on a presetter, CNC machining center
- Mechanization
- Pre-staging
- Stamping press
Die carts at bolster height, stamping press
Dies used to move by forklift, and the press waited for the truck and for the driver to nudge each die into line. Now dies travel on carts at bolster height, roll on and off over rollers and stop against fixed stops in the right position.
Illustrative numbersBefore: stopped 51 min, 16 min of it external work. After: stopped 21 min, plus 10 min done while running. The stop is 30 min shorter.
Step by step (5 steps)
1. 1Bring the new die to the pressBefore: 10 min, stopped (external work)After: 5 min, while running
2. 2Take out the old dieBefore: 9 min, stoppedAfter: 3 min, stopped
3. 3Put the new die in place and line it upBefore: 11 min, stoppedAfter: 3 min, stopped
4. 4Clamp, then trial strokes to the first good partBefore: 15 min, stoppedAfter: 15 min, stopped
5. 5Take the old die back to the rackBefore: 6 min, stopped (external work)After: 5 min, while running
What it took:
Two die carts at bolster height, rollers or ball rails in the bolster, fixed stops and aisle space for the carts. Shingo puts mechanization last: spend here after the cheaper stages, and only where moving the die is a long step.
Longest step now:
Clamping and trial strokes, 15 min. See the quick clamps and standard die height examples.
Keep it:
Carts park in marked spots by the press and are on the maintenance plan. The die height and locating standard is written down, so new dies fit the carts and the stops.
See also: Quick clamps instead of bolts on a press, Standard die height, no shut height adjustment
- Pre-staging
- Parallel work
- Assembly line
Parts kits delivered before a model change, assembly line
The line used to stop while operators cleared old parts and a material handler fetched the new model's parts. Now the water spider delivers the new model's parts in kits before the stop, only the last kit's leftovers remain, and each operator changes the fixture at their own station at the same time.
Illustrative numbersBefore: stopped 47 min, 15 min of it external work. After: stopped 16 min, plus 15 min done while running. The stop is 31 min shorter.
Step by step (5 steps)
1. 1Clear leftover parts of the old model from the stationsBefore: 10 min, stoppedAfter: 4 min, stopped
2. 2Fetch parts for the new model from the warehouseBefore: 15 min, stopped (external work)After: 15 min, while running
3. 3Change the fixtures at three stationsBefore: 9 min, stoppedAfter: 3 min, stopped
4. 4Find and read the work instructions for the new modelBefore: 5 min, stoppedAfter: 1 min, stopped
5. 5Build and check the first unitBefore: 8 min, stoppedAfter: 8 min, stopped
What it took:
A kit cart per model, the change added to the water spider's route at a set time, and every operator trained to change their own fixture. Work instructions for each model are posted at the station.
Longest step now:
Building and checking the first unit, 8 min. Keep it; it proves every station changed correctly.
Keep it:
The kit delivery time is on the schedule next to the model change. Leftover parts after a change are counted, since they show whether the kits are the right size.
See also: Materials, labels and change parts staged for a packing line

Every example here is illustrative. The steps are typical for that kind of machine and the minutes are round numbers chosen to show the method, not measurements from a company. Your own steps and times come from filming your own changeover. Lockout, crane, hot-surface and line clearance steps stay in the changeover even when they are slow; nothing on this page replaces your site's safety and quality rules.

Do it on your line

One changeover, one machine, in this order. The SMED worksheet and the changeover checklist below are built for these steps.

1Pick the machine where changeovers cost the most: the bottleneck, or the one forcing the biggest batches.
2Film one whole changeover from the last good part to the first good part at normal speed, including the slow-down and the run-up.
3Watch it with the setter and list every step with its time on the SMED worksheet, marked internal or external. Say that the method is the target, not the people.
4Move every external step outside the stop: a checklist, a cart with everything on it, and no stop until the cart is complete.
5For each internal step left, ask what would let it happen off the machine: preheat, preset, set up on a spare plate, or make the height or clamping edge the same on every tool.
6Shorten the rest: one-turn or no-turn fasteners, a second person with a written split of tasks, and fixed stops or marked settings instead of trial and adjustment.
7Keep every safety and quality step, such as lockout, crane rules, hot surfaces and line clearance, even when it is slow.
8Write the new sequence as the standard, train it, and time every changeover against it on the changeover checklist.
9Decide what the saved minutes are for: more output on a bottleneck, or more changeovers and smaller batches. The EPEI calculator shows how often each product can then come round.
10Start again on the longest step that is left.

The method behind the examples

Shigeo Shingo set out SMED in A Revolution in Manufacturing: The SMED System (Productivity Press, 1985). He describes a preliminary stage, in which internal and external work are mixed together, and three conceptual stages: separate internal and external setup, convert internal setup to external, and improve every part of both. The examples on this page are grouped in that order.

Shingo's eight techniques are: separate internal from external setup, convert internal to external, standardize the function rather than the shape, use functional clamps or remove fasteners, use intermediate jigs, work in parallel, eliminate adjustments, and mechanize. The technique filter follows that list, with checklists, function checks, pre-staging, shadow boards and visual markings added as the everyday ways of doing them.

Single minute means under 10 minutes, a single-digit number, not one minute. Changeover time runs from the last good part of the old run to the first good part of the new one, so trial parts and adjustments count. Sugai, McIntosh and Novaski (2007) add that the slow-down before the stop and the run-up after it are lost time too, and that SMED on its own does not measure them, so time the whole loss.

Two cautions. Who first cut die changes at Toyota is disputed (our review of Shingo's book covers it), and the results Shingo reports are case reports rather than controlled studies. Neither changes the order of work the examples follow: separate, convert, then shorten what is left.

Sources checked

Shingo, A Revolution in Manufacturing: The SMED System (Productivity Press, 1985), publisher's page and contents: Title, publisher and year; chapters on the fundamentals of SMED, its techniques and applying it to internal operations.
Lean Enterprise Institute, Lean Lexicon: single-minute exchange of die: Single minute means under 10 minutes; internal and external setup defined.
Sugai, McIntosh and Novaski, Shingo's methodology (SMED): critical evaluation and case study, Gestão & Produção 14(2), 2007: Shingo's preliminary stage and three conceptual stages as set out in the 1985 book; run-down and run-up losses that SMED leaves out.
Wikipedia, Single-minute exchange of die: Shingo's eight techniques, cited there to A Study of the Toyota Production System (Productivity Press, 1989); his point that only the last turn of a bolt tightens it.
Our review of Shingo's SMED book: Edition details, the dispute over the Toyota history and the published critiques.

Go deeper

The cards are the short version. These guides explain the method and walk through examples in full.

All our articles on this subject are in the value stream mapping and flow topic.

Free templates and tools

Key terms

Lean glossary

Doing this in LeanSuite

SMED
Runs each changeover as a timed checklist, and AI splits a filmed changeover into internal and external tasks.
See SMED

FAQ

Questions about SMED examples

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SMED examples: 16 changeovers, before and after

Stage 1: separate internal and external work

Checklist and staged cart on a stamping press

Next mold checked and parked before the stop

Materials, labels and change parts staged for a packing line

Stage 2: convert internal work to external

Mold preheated off the machine

Feeders loaded on a spare trolley, SMT line

Tools measured on a presetter, CNC machining center

Fixture set up on a spare plate, CNC machining center

Standard die height, no shut height adjustment

Stage 3: shorten the internal work that is left

Quick clamps instead of bolts on a press

Two people in parallel on a mold change

Fixture keys in the table slot instead of indicating

Guide rails set to marked positions, case packer

Color-coded change parts with hand knobs, bottle labeler