SINGLE MINUTE EXCHANGE OF DIES

(SMED)

What is a Changeover?

The amount of time taken to change a piece of equipment from producing the last good piece of a production lot to the first good piece of the next production lot.

Total elapsed changeover time, Tc =Run-down period + Set-up period + Run-up period

3

What is SMED?

Single Minute Exchange of Dies

Developed by Shigeo Shingo

A system designed to radically reduce the amount of time to perform a changeover or setup

History

The concept arose in the late 1950s and early 1960s, when Shigeo Shingo, was consulting to a variety of companies including Toyota, and was contemplating their inability to eliminate bottlenecks at car body-moulding presses.

• 1950-Forms first stage of SMED : Involves splitting a setup operation into internal and external set ups

• 1956-58—Worked for Mitsubishi Ship buildings• Invents a new system for hull assembly of 65,000 ton super-

tanker• Cut time from four months down to three and than two

months• 1970-Originated SMED system at Toyota • Wrote more than 14 books

• Including Toyota Production System

Pit stop in F1 Race

https://www.youtube.com/watch?v=RRy_73ivcms

The reduction of time in pit stops during F1 races is one of the beautiful example of SMED.

Reducing Set-Up Time

Stages Of SMED

TOTA

L SE

T U

P T

IME

INT

ER

NA

L SE

T U

P T

IME

120 MINS

STAGE I

Segregate Internal External Elements

STAGE II

Convert some Internal Elements or parts of those to External Elements

STAGE III

Reduce times of residual Internal Elements

80 MINS

40 MINS

7 MINS

The SMED Process

Observe the current methodology.Separate internal and external Operations.Identify the tasks which can be eliminated.Convert maximum internal operations to external

Operations.Streamline the remaining Internal activities.Streamline External activities.Document the new procedure and the actions that

are yet to be completed. Do it all again.

1. Observe the current methodology

Watch a full changeover at least once – more is better.

Do documentation of all the activities happening during the changeover.

Data recording Format

Company NameProcess : Roll Change Area : Machine No : Start Time : Name :

S.No. ACTIVITY TIME(min) INTER

NALEXTERNAL

NEEDED WORKS

MOTION

TRANSPORTATION

WAITING

SEARCHING

ELIMINATE

COMBINE

REDUCE

SIMPLIFY

REMARK

                             

                             

                             

                             

                             

                             

                             

                             

                             

                             

                             

                             

                             

Look for

Shortages, mistakes, inadequate placement of needed equipment.

Equipment with slow adjustments for the large coarse part of adjustment.

Proper placing of all required equipment which are used.

Lack of functional standardization, that is standardization of only the parts necessary for setup, e.g. all bolts use same size spanner, Same type of bolts used, die grip points are in the same place on all dies.

Look for

Much operator movement around the equipment during setup.

More attachment / bolting points than actually required.

Attachment points that take more than one turn to fasten.

Any adjustments after initial setup.Any use of experts during setup.If there is waiting for anything.

2. Separate internal and external Operations.

Separate the INTERNAL and EXTERNAL activities.

External Operation : One that may be completed while machine is in operation.

Internal Operation : One that requires the shut down of the machine for completion.

3. Identify the tasks which can be eliminated.

Look for operation / tasks which can be eliminated like, waiting for tools, waiting for crane, etc..

4. Convert maximum internal operations to external Operations

Convert (where possible) Internal activities into External ones.

5. Streamline the remaining Internal activities

Simplify the remaining internal activities

For e.g. It's the last turn of a bolt that tightens it; the rest is just movement.

And also adopt parallel operations.

The interrupted screw (or interrupted thread) provides one means of clamping and unclamping something quickly.

6. Streamline External activities.

Complete all the external Activities before the change over happens.

7. Document the new procedure and the actions that are yet to be completed.

Document all the activities which occurred.

Note all the activity which are not completed and make action plan.

8. Do it all again

Repeat all the steps for the next change over.

Example Tools

Split thread bolts

Example Tools

Example Tools

Reduce the amount of turns required in order to activate the screw.

Shadow Board

Benefits of SMED

• Increases throughput by reducing setup times

• Eliminates setup errors• Increases safety• Reduces the cost of setups• Reduces waiting times and inventory

buildups• Reduced setup time