md. imrul kaes - smed system 2013-4-17

7/28/2019 md. Imrul Kaes - SMED SYSTEM 2013-4-17

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SINGLE MINUTE EXCHANGE OF DIES (SMED)

OR

QUICK CHANGE OVERTIME


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1885: Ford was able to transform iron ore into anautomobile in just 33 hours by assembly line production,transforming craft production to mass production.

Changeover

time

Lot size Operation

time per item

Operation

time including

changeover

time

Ratio

8 hours

(480 min)

100 1 min 5.8 min 480%

8 hours 1,000 1 min 1.48 min 48%

8 hours 10,000 1 min 1.048 min 4.8%

Tuesday, April 16, 2013 2MD. IMRUL KAES


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Many companies produce large lots simply because long

changeover times make it costly to frequent change products.

Large lot production has several disadvantages:

Inventory waste: ties up company resources without adding

any value to the product.

Delay: customers must wait for the companys entire lots

rather than just the quantities a customer needs.

Declining quality: storing unsold inventory increases the

chance that it will have to be scrapped or reworked, which

adds cost to the product.



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Customers today want a variety of products in just the

quantities they need. They expect high quality, a good priceand speedy delivery. Producing to customer requirements

means getting batch processes to produce in small lots. Doing

this usually creates a need to reduce set up times.



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What is SMED?

SMED, stands for Single-Minute Exchange of Die, is a

theory and techniques for performing setup operations in

under ten minutes, i.e., in a number of minutes expressed

in a single digit.

The SMED method was revolutionized by Mr. Shingo since

1950 in Japan. Land costs in Japan were very high,

therefore it was not feasible to store large inventories of

vehicles.

The concepts and techniques became available to other

countries started around 1974 in West Germany and

Switzerland and in 1976 in Europe and United States.



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6

3000-ton sheet metal stamping press

Before: 4 hours After: 3 minutes

Now the same press can make multiple parts (hoods and

doors in this case) for the Camry, only what is needed for the

next hour of production.

400-ton LIM molding press with 16-cavity tool Before: 3 hours

After: 18 minutes Increase in effective capacity equal to 5,184 additional parts

Tuesday, April 16, 2013 MD. IMRUL KAES


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Changeover : the total process of changing a production line

from running one product to another.

Changeover time: elapsed time between the last good

previous product and the first good next product at the right

speed.

setup time: the time to adjust or replace machine parts to

accommodate the new product.

Start up time: the time to bring the process up to the right

speed and quality.

Changeover time = set up time + start up time



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Most often the changeover happens like below figure shows,

when the last part from production batch is processed.

Breakdown of changeover duration:

Dismount

tools

Mounting

new tools

Trials Adjustments



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REMOVING TOOLS USED & MOUNTING NEW TOOLS: This includesremoval of parts, equipment, tools, etc., from the machine aftercompleting a production run and mounting of tools etc., for thenext production run.

POSITIONING, ALIGNING AND SETTING: This step covers all the

positioning and aligning of tool parts that must be made in theprocess of setting up before starting production operation.

TRIAL RUNS AND ADJUSTMENTS: In this process, parts areproduced, checked for correctness and accuracy, adjustments madein the setting, further parts produced and the process repeated tillcorrect components are produced. The number of such trials andthe length of time it takes to achieve correct setting, depends onthe experience and skill of the person doing the setup.



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SET UP TIME BREAK-UP

PROPORTION OF TIMEOPERATION

REMOVING TOOLS USED AND

MOUNTING NEW TOOLS

15 %

POSITIONING, ALIGNING AND

SETTING OF TOOLS

25 %

TRIAL RUNS AND ADJUSTMENTS 60 %



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Types of changeover costs Types of

changeover costs

Tangible costs - Costs for which a reasonably accurate dollar

value may be calculated.

Intangible costs - Costs which are difficult or impossible to

quantify.

The fact that a cost cannot be dollarized does not mean it is

not expensive!



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Lost production

Suppose,

Line production rate = 300 pcs/hr

Profit = $3/pc

Average changeover time per line per day = 1 hrChange over profit loss per day per line = 300 x $3 = $900

Changeover cost per year (300 days) for 1 line

= 300 x $900 = $270000

If a company runs 100 line = 100 x $270000 = $27,000,000



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Labor cost

Per hour salary of 1 worker = $0.25 / hr

Labor cost per day per worker= $0.25 / hr

If there are 40 workers per line, cost = $10/day

= $10 x 300 =$3000/year/lineIf there are 100 line, then cost = 100 x $3000 = $300,000/per

year for the whole sewing lines.



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Machine cost

Suppose, you have to rent on an average 5 machine for each line

every day.

The rent of each machine is $4

You have 100 line and 300 working days in a year.

So the rent cost when the machine is idle

= 5x100x300x$4

=$600,000/ year



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Key elements of changeover

Internal activities: must be performed while machine or

process is stopped that is not producing parts.

Examples of internal activities are:

Removing guides and folders from the machines.

Cleaning down the work surface.

Fixing new guides and folders in machines. Trial run and adjustment the machine.



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External activities: can be performed whilst the machine or

process is running that is making parts.

Examples of external activities are:

Getting instructions for the next style.

Getting material for the next style from store.

Getting tools for next style from store.

Arranging for machine carriers/lifting equipments to be

available when required. New layout outline.

Collection of sample and technical sheet.



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Changeover activity detail

Producing good

parts--------------------

---Machine down --- -Producing bad parts- ----------Producing

good parts

Production on Production off Production off/slow Production on

EXTERNAL SETUP INTERNAL SETUP INTERNAL SETUP EXTERNAL SETUP

Pre-staging Machine down time Adjustment time Post stagingTo prepare for

changeover

To exchange tools To make first good

piece

To return work

station to

standard

Actual CHANGE OVER

TIME



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6 steps of SMED methodology

1. Observe the current changeover process:

by video

by time study

2. Identify internal and external activities:

Internal: activities to be performed whilst the machine is

stopped.

External: activities that can be performed away from themachine, while the line is running.



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3. Convert activities from internal to external setup

Example : setting guide and folders to similar extra machines

outside the line.

4. Increase efficiency of the remaining internal activities (or

reduce internal activities)

Minimize or eliminate adjustments

Parallel operations (electrical socket + guide-folder setupsimultaneously)

Develop team work.



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TOTALSETUPTIME

INTERNALSETUPTIME

120 MINS

STAGE I

Segregate

Internal

External

Elements

STAGE II

Convert some

Internal

Elements or

parts of those toExternal

Elements

STAGE III

Reduce times of

residual Internal

Elements

80 MINS

40 MINS

7 MINS



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5. Optimize the start up time

Minimize or eliminate adjustments

make the adjustment easy.

6. Increase efficiency of external activities (or reduce external

activities)

Apply 5s principles.



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Analyze all changeover activities

Observe, describe and map the change over process.

Determine all activities in the changeover process.

Start to think which are internal and external elements.

I E E I E I I E E I



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Separate internal activities from external activities:

Convert internal activities into external activities:

Take advance preparation for changeover.

Simplify and standardize the changeover process andtools.

Remove critical activities if possible.

I I I I I E E E E E

I I I E E E E E E E



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Streamline internal activities:

Simultaneous operations.

Team work to quickly hit the set-up activities.

Develop one touch operations.

I I E E E E E E E



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Streamline external operation:

Reduce effort, motion and distances.

Determine optimum storage location.

Establish user friendly systems. For example sign off

procedure.

I I E E E E E



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Case study: changeover activity in sewing section

1. Some internal activities found in sewing section, which are:

Nose, needle, thread change

New lopper adjustment New guide, folder adjustment

Trial run and adjusting the machine.



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Some external activities found in the sewing section, which are:

Getting instruction about new style from the planning

department.

Getting fabrics, thread and other activities from cutting and

store section.

Getting needle, guide and other tools for the new style from

maintenance department.

Returning tools from the last operation to maintenance

department.



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Style 1Operation

no.

Operation name M/C name Should take

(min)

Actually taking

(min-sec)

1 Care label Plain mc 2 5-10

2 Shoulder join OL 5.5 74

3 Rib make Plain mc 1 50

4 V-tack (2) Plain mc 1 7

5 V-neck join (2) OL 7 83-43

6 Neck top seam Flat lock 10 59

7 Neck TST Plain mc 1 19

8 Main label join Plain mc 1 30

9 Sleeve join (2) OL 5 30-20

10 AHTS Flat lock 10 49

11 Side seam (2) OL 5 17

12 Body hem Flat lock 10 60-38

13 Sleeve hem Flat lock 10 35-45



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Changeover information:

Total expectedchangeover time

(min)

Actualchangeove

r time

(min)

Productionday 1

Productionday2

SMVrequired

to

produce

each

product

69 529.85 130 380 6.554



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Impact of changeover time on production rate

Production is hampered due to excess changeover time.

The production increased 250 pcs the day immediate after thechangeover day.

Production rate increased from 13 pcs per hour to 38 pcs per

hour.



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Impact of changeover time on WIIP stock

There is a significant increase in WIP stock due to excess

changeover time.

Extra space or container is needed for extra WIP.

Linear relationship between changeover time and WIP.

For every 10 min changeover time 9.18 pcs of WIP stock.



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Change overtime

WIP

stock



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Impact of changeover time on production lead time

Changeover time is high due to various internal activities and

machine problems, long start up time as worker make delay to

start her operation for various problem such as input

problem.

Due to excess changeover time extra time is required to

complete the production. As a result lead time for production

is increased.

We saw in the case that around 460 min were required for

excess changeover time.



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Impact of change over time on defects

Long changeover time - higher defects.

In the case, on the changeover day defective items were 112where avg defects per day were 86.

It follows a linear relationship. It has been analytically found

that for each excess 10 min of changeover time the number of

defect is 1.01



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Change overtime

Number of

defects



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The reason behind excess changeover time

Changeover operations start after the last good piece of

previous style passes last operation.

High searching time for proper tools.

Delay due unavailability of input in the time it required.

No team work, only maintenance person or operator for that

particular machine do the machine set up.

Guides and folders are not standardized.



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Advantages of set up reduction

Production of small lot sizes with an increased number of

changeover.

Reduce lead time.

Reduction of changeover cost.

Trial runs are minimized because operations are simplified

and auto-machines are used.

Urgent orders can be quickly produced.

Reduction of inventory cost. Set up becomes easy, no special skills are needed.

Better quality because of less inventory defects.



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SETUP REDUCTION RESULTS

COMPANY MACHINE BEFORE: AFTER:

Toyota Boltmaker 8 hrs. 58 sec.

Mitsubishi 6 Arbor Borer 24 hrs. 2.7 min.

Arakawa 500 Ton Press 27 min. 4.5 min.

Toyoda Cold Forge 32 min. 7.5 min.

Hitachi Die Cast 75 min. 3.0 min.

HP IC Insert 30 min. 3.0 min.

Omark Press 120 min. 3.0 min.

India Meters Press 90 min. 5.0 min.

Autolec CNC Turning 240 min 10.0 min.

Tube Products Tube Mill 480 min. 120.0 min.

T d A il 16 2013 38MD IMRUL KAES

md. imrul kaes - smed system 2013-4-17

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