Poka Yoke - Vietnam World Class Manufacturing
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Transcript Poka Yoke - Vietnam World Class Manufacturing
STM Quality
Limited
Poka-Yoke
TOTAL QUALITY MANAGEMENT
Poka-Yoke
©©ABSL
Power Solutions
STM Quality
Limited 2007
What is Poka-Yoke?
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This is known as ‘MISTAKE-PROOFING’
From Japanese:
Yokeru (avoid)
Poka (inadvertent errors)
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What Does Poka-Yoke Do?
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Eliminates the cause of an error at the
source;
Detects an error as it is being made;
Detects an error soon after it has been
made but before it reaches the next
operation.
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Are Errors Unavoidable?
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There are two approaches to dealing
with errors:
1. ERRORS ARE INEVITABLE!
2. ERRORS CAN BE ELIMINATED!
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1. Errors Are Inevitable
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People always make mistakes.
While we accept the mistakes as natural,
we blame the people who make them.
With this attitude, we are likely to
overlook defects as they occur in
production.
They may be detected at final inspection,
or worse still, by the customer.
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2. Errors Can Be Eliminated
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Any kind of mistake people make can
be reduced or even eliminated.
People make fewer mistakes if they are
supported by proper training and by a
production system based on the
principle that errors can be avoided.
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Inspection
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One method of detecting errors is
inspection.
There are two major types of
inspection.
1. SAMPLING INSPECTION.
2. 100% INSPECTION.
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Sampling Inspection
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In some factories, the attitude is:
“It may take all day to inspect all
product”.
“There may be a few defects, but
sampling is the most practical way to
check”.
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Sampling Inspection - Reflection
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Think about sampling.
With sampling, there is a chance that
an error may go undetected.
Even if 1 part in 1000 is defective, the
customer who buys that part has a
100% defective product!
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Sampling Inspection - Reflection
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SAMPLING INSPECTION MAKES
SENSE ONLY FROM THE
MANUFACTURER’S VIEW, NOT FROM
THE CUSTOMER’S!
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2. 100% Inspection
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In the best factories, the attitude is:
“We won’t tolerate a single defect!”
“We will organize production so that
100% of the product can be easily
inspected”.
“That makes the most sense”.
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100% Inspection - Reflection
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Think about 100% inspection.
Even one defective product is enough to
destroy a customer’s confidence in a
company.
To stay competitive a company must
supply good product in thousands.
The best way to achieve this is to
organize production to inspect 100% of
the products.
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The User Is The Best Inspector
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No one intends to make mistakes.
While we are working, errors can show
up without us noticing.
How can we catch these errors before
they turn into defective products?
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Finding Defects in the
Subsequent Process
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We don’t expect to find defects, but if a
product we use doesn’t do what it is
supposed to do, then we know it is
defective.
Users are the best at discovering
defects!
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Finding Defects in the
Subsequent Process
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Since subsequent processes are also
‘users’ of the product being
manufactured, they are also expert at
finding defects.
If products are produced in a flow, each
product is sent to the next process as
soon as it is finished and defects are
therefore found immediately.
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Two Strategies for Zero Defects
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1. DON’T MAKE IT!
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1. Don’t Make It!
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Don’t make product you don’t need.
The more you make, the greater the
opportunity for defects.
Follow ‘just-in-time’ principles by only
making what is needed, when it is
needed in the amount needed.
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Two Strategies for Zero Defects
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2. Build Safeguards
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2. Build Safeguards
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The user is an expert in finding defects.
Therefore build safeguards into the
production process.
Quality can be built into products by
implementation of Poka-Yoke.
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Poka-Yoke Devices
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Human errors are usually inadvertent.
Poka-yoke devices help us avoid
defects, even when inadvertent errors
are made.
Poka-yoke helps build quality into
processes.
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Poka-Yoke Devices
– Error Detection and Alarms
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Poka-Yoke Devices
– Checklists
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Poka-Yoke Example
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It is possible to mount the blank the
wrong way onto the pierce tool.
BLANK
PIERCED BLANK
INCORRECT
As the blank can fit the pierce tool in
many ways, how can this be prevented?
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Poka-Yoke Example
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By fitting a block into the pierce tooling,
the blank plate can only go on one way.
BLOCK
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Poka-Yoke
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POKA-YOKE
MEANS
ZERO DEFECTS
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