SMED
What is SMED?
SMED stands for Single Minute Exchange of Die. The
SMED system is theory and set of techniques that make it
possible to perform equipment set up and changeover
operations in under 10 minutes – in others words, in the
single minute range. SMED was originally developed to
improve die press and machine tool set-ups, but its
principles apply to changeovers in all types of process.
It is important to point out that if may not be possible to
reach single minute range for all Set ups, but SMED does
dramatically reduce Set up times in almost every case.
Why SMED is important for companies?
Customers today want a variety of
products in just the quantities they need.
They expect high quality, a good price,
and speedy delivery SMED helps meet
these customer needs with less waste by
making it cost – effective to produce
things in smaller quantities, or lots.
The trouble with large lot production:
Large lot production has several disadvantages:
 Inventory waste: storing what is not sold costs money
and ties up company resources without adding any
value to the product.
 Delay: Customers must wait for the company to
produce entire lots rather than just the quantities a
customer needs.
 Declining quality: Storing unsold inventory increase
the chance that it will have to be scrapped or
reworked, which adds cost to the product.
The Benefits of SMED:
SMED changes the assumption that set ups can be done
quickly, they can be done as often as needed. This
means companies can make products in smaller lots,
which has many advantages:
 Flexibility: companies can meet changing customer
needs without the expense excess inventory.
 Quicker delivery: small lot production means fewer
customers waiting time.
 Better Quality: less inventory storage means fewer
storage related defects. SMED also lowers defects by
reducing Set up errors and eliminating trial runs of
the new products.
 Higher productivity: Shorter changeovers reduce
down time, which means a higher equipment
productivity rate.
The benefits of SMED for you
SMED also benefit you and also company
employee. First quicker set up support job security
by strengthening the companies competitiveness.
In addition SMED make daily production work go
smoother because:
 Simpler set up results in safer change over with
less physical strain or risk of injury.
 Less inventory means less clutter in the work
place, which makes production easier and safer.
 Set up tools are standardise and combined which
means fewer tools to keep track of.
Basic Steps In a Set up Operation
1-Preparation, after process adjustments, checking of
material and tools
2-Mounting and removing tools and parts
3-Measurements, settings and calibrations
4-Trial runs and adjustments
1-Preparation, after process adjustments,
checking of material and tools
This step ensures that all part and tools are where they
should be and that they are functioning properly. Also
included in this step is the period after processing
when these items are removed and returned to storage,
machinery clean and so forth.
In a traditional set up, parts of the preparation step
are done after the machine is stopped. This step should
be done as external set up, while the equipment is still
running.
2-Mounting and removing tools and parts
This step includes the removal of parts and tools after
one product is processed, and the attachment of the
parts and tools for next product.
Generally the machine must be stopped to do this
step, so it is internal set up. This internal set up step
the actual changing over takes very little time
compared to the other steps.
3-Measurements, settings and calibrations
This step refers to all the measurements and
calibrations that must be made in order to perform a
production operation, such as centring, dimensioning,
measuring temperature or pressure and so forth.
Although the equipment must be stopped for this
step, the SMED system teaches ways to do these tasks
quickly by preparing the equipment is running.
4-Trial runs and adjustments
In the final steps of the traditional set up operation,
adjustments are made after a test piece is machined.
The more accurate your measurements and
calibrations are in the previous step the easier these
adjustment will be.
Correct adjustment of the equipment is one of the
most difficult tasks in a set up operation. In traditional
set up, the time needed for trial runs and adjustments
depends on personal skill.
In a traditional set up the machine is not making
good products until this step is finished, it is
considered part of internal set up. SMED teaches ways
to eliminate this step completely, so that the machine
makes good products right after it is started up.
Steps in set up
1-Preparation, after process adjustments, checking
Proportion of set up time
before SMED improvements
30%
of material and tools
2-Mounting and removing tools and parts
5%
3-Measurements, settings and calibrations
15%
4-Trial runs and adjustments
50%
Analysing your Set up operations
The main reason traditional Set up operations takes
so long is that internal & external Set ups are
confused. Many tasks that could be done while the
machine is still running aren’t done until the machine
is stopped.
The three stages of SMED are described &
designed to simplify and shorten changeovers. But
before you start applying SMED, you need a clear idea
of how you currently perform Set up operations and
how long each steps takes.
The preliminary step, called a Set up analysis, will
help you how to implement SMED improvement on
your equipment. Set up analysis has three main steps:
1-Videotape the entire Set up operation focusing on
the hand, eye, and body movements of the person
doing the Set up. Use the camera’s time and date
function if there is one.
2-Show the video to the Set up person and other
people involved with the equipment. Ask the Set up
person to describe what he is shown doing. Have the
group share their thoughts about the operation.
3-Study the video in detail, noting the time and
motions involved in each step of the Set up. Use the
video players pause and rewind functions as needed.
Also use a stop watch if necessary.
The three stages of SMED:
Stage 1:separating internal & external Set up
The most important step in implementing SMED is
distinguishing between internal and external Set up.
By doing obvious things preparation and transport
while the machine is running, the time needed for
internal Set up, with the machine stopped, can usually
cut by as much as 30 to 50 percent.
Stage 2:Converting internal set up to
external Set up
Further reducing Set up times toward the single
minuet range involves two important activities: 1) reexamining operations to see whether any steps are
wrongly assumed to be internal Set up, and 2) finding
ways to convert these steps to external Set up.
Operation can often be converted to external Set up by
looking at the true function.
Stage 3:Streemlining all aspects of the Set up
operation
To further reduce Set up time, the basic elements of
each Set up are analysed in detail. Specific principles
are applied to shorten the time needed, especially for
steps that must be done as internal Set up, with the
machine stopped.
Description of stage 1:
There are three techniques help us separate internal
external Set up tasks. These techniques are: using
checklists, performing function checks, and improving
transport of die and other parts.
Checklists:
A checklist lists everything required to set up and run
the next operation. The list includes such items as:
 Tools, specifications, and workers required.
 Proper values for operating conditions such as
temperature, pressure etc.
 Correct measurement and dimensions required for
each operation
Checking item of the list before the m/c is stopped
helps prevent mistakes that come up after internal set
up begun.
Function checks:
Function checks should be done well before Set
up begins so that repair can be made if
something does not work right. If broken dies,
moulds, or jigs are not discovered until test runs
are done, a delay will occur in internal Set up.
Making sure such items are in working order before
they are mounted will cut down set up time a great
deal.
Improved transport of parts and
Tools:
Dies, tools, jigs, gauges, and other items needed for
an operation must be moved between storage areas
and machines, then back to storage once a lot is
finished. To shorten the time the machine is shut
down, transport of these items should be done during
external set up. In other words, new parts and tools
should be transported to the machine before the
machine is shutdown for changeover.
Stage 2: Converting internal set up to
external Set up
I-Advance preparation of conditions:
Advance preparation of conditions means getting
necessary parts tools and conditions ready before
internal set up begins. Conditions like temperature,
pressure, or position of material can be prepared
externally while the machine is running.
(Ex. Pre-heating of Mould or Material)
II-Function standardisation:
SMED uses a
targeted approach call function standardisation. It
would be expensive and wasteful to make external
dimensions of every die, tool or part the same,
regardless of the size or shape of the product it
forms. Function standardisations avoid this waste by
focusing on standardising only those elements whose
functions are essential to the set up. Function
standardisation might apply to dimensioning,
centeing, securing, expelling, or gripping for
instance.
Implementing Function standardisation: involves two
steps:
1- Look closely at each individual function in your
set up process and decide which functions if any
can be standardise.
2- Look again at the functions and think about
which can be made more efficient by replacing
the fewest possible parts.
(Exp.clamping Function standardisation)
Streamlining external set up:
External set up improvement include streamlining
the storage and transport of parts and tools. In
dealing with small tools, dies, jigs, and gauges, it is
vital to address issue of tool and die management.
You need to ask yourself questions such as:
 What is the best way to organise these items?
 How can we keep these items maintained in
perfect condition and ready for the next
operation?
 How many of these items should we keep in
stock?
Improving storage and transport:
Operation for storing and transporting dies can be very
time consuming, especially when your company keeps a
large no. of dies on hand. Storage and transport can be
improved by marking the dies with colour codes, and the
location numbers of the shelves where they are stored, the
shelves are also marked.
Streamlining internal set up:
Through improvement in internal setup operations are
next. These include implementing parallel operations,
using functional clamps, eliminating adjustments, and
mechanization.
I. Implementing parallel operations:
Machines such as plastic moulding machine, and die
costing machines often require operation at both the
front and back of the machine. One person changeovers
of such machines mean wasted time and movement
because the same person is constantly walking back and
forth from one end of the machine to the other.
Parallel operations divide the set up operation between
two people, one at each end of the machine.
When set up is done using parallel operations, it is
important to maintain reliable and safe operations and
minimize waiting time. To help streamline parallel
operations, workers develop and follow procedural
charts for each set up.