EK KADAM
FOUNDATION
"Accelerating Youth- Accelerating Nation"

Concept Behind Poke Yoke Poke-Yoke
( Check out for all our Problems - Why, Why analysis )
- Albert Ainstein

Approaches to deal with errors Poke-Yoke
• We blame people who make
mistakes
• With this problem is not solved but
lowers morale of people.
Errors are inevitable
• People make fewer mistakes if
they are supported by proper
training and production system.
Errors can be eliminated

Concept Behind Poke Yoke Poke-Yoke
The term “ Error ” means a sporadic deviation from standard procedures
resulting from loss of memory, perception or motion of human being.
Defect Vs Errors
Error Defect
Cause Result

Concept Behind Poke Yoke Poke-Yoke
Causes of Errors :
• Inadequate written standards
• Too many parts
• Mix up
• Too many steps
• Too many adjustments
• Tooling change
• Frequent repetition
• Environmental factors
• Specifications / critical conditions

Errors and safeguards Poke-Yoke
1. Forgetfulness - Alerting operator in advance or checking at
regular intervals.
2. Errors due to - Training, standardizing work procedure.
misunderstanding
3. Errors in identification - Training, attentiveness and vigilance.
4. Errors by amateurs - Skill building & standardization.
5. Willful errors - Basic education & experience.
6. Inadvertent errors - Attentiveness, discipline, work standardization.
7. Errors due to slowness - Skill building, work standardization.
8. Errors due to lack of - Work standardization & work instructions.
Standards
9. Surprise errors - Work standardization, TPM.
10. Intentional errors - Fundamental education, discipline.
Different kinds of errors Safeguards
Almost all mistakes can be prevented if we take time to identify and why they
happen and then take steps to prevent them by using Poka-yoke methods and
the safeguards listed above.

Concept Behind Poke Yoke Poke-Yoke
Poka - yoke is a technique for avoiding simple human errors at work.
Part of “Zero Quality Control” developed by Dr. Shigeo Shingo.
Yokeru to avoid
poka Inadvertent mistakes
People make fewer mistakes if they are supported by proper training
and by introducing good system.
Errors can be eliminated

Concept Behind Poke Yoke Poke-Yoke
Normal functions
stopped when
defect predicted
Even intentional
errors are
impossible
Signals
Abnormality / Error
about to occur
Normal functions
stopped when
defect detected
Defective Items
cannot pass on
process
Signals that
defects have
occurred
STATE FUNCTION
DEFECTS
About to occur (Prediction)
SHUT
DOWN
CONTROL
WARNING
POKA
FLOW
CONTROL
WARNING
Occurred (Detection)
SHUT DOWN
CONTROL
WARNING
SHUT DOWN
∩
∩
∩
STOP !
Flash lights
Hooter

Avoiding defects at the source Poke-Yoke

Eight principles of basic improvement Poke-Yoke
3. Stop doing it wrong and start doing it right-now!
1. Build quality into processes
2. All inadvertent errors and defects can be eliminated
6. Mistakes and defects can be reduced to zero when everyone works
together to eliminate them
4. Don’t think up excuses, think about how to do it right
5. A 60% chance of success is good enough - implement your idea now!
8. Seek out the true cause, using 6 W’s and 2 H
7. Ten heads are better than one

Two target directions Poke-Yoke
• Exclude the possibility for mistakes at Development stage.
Target group : Product designers, process planners.
• Stop the blunders (mistakes) committed at once.
Target group : Learn start groups, foreman, setters.

Levels Poke-Yoke

Levels Poke-Yoke

Levels Poke-Yoke

Poka-yoke hints Poke-Yoke
1. Identify items by their characteristics
• By weight:
Establish weight standards.
• By dimension:
Establish standards for length,
width, diameter, etc.
• By shape
Establish standards for shape
characteristics such as angles,
depressions, projections, curvature,
or position of holes.

Poka-yoke hints Poke-Yoke
2. Detect deviation from procedures or omitted process
• Process sequence method:
The subsequent work cannot be
performed if the prescribed
sequence is not followed.
Cannot be
drilled after
bending
Incorrect procedure
• Process to process sequence method:
Operations cannot be performed if one of a series
of processes has been omitted.

Poka-yoke hints Poke-Yoke
3. Detect deviations from fixed values
• Using a counter
A fixed number, such as the number of
operations or parts, is used as a reference.
• Odd-part-out method
When a number of parts are
assembled as a lot. The exact
number of parts needed is
prepared.
• Critical condition detection:
A critical manufacturing condition such
as pressure, current, temperature, or
time is measured.
Leftover
parts

Poka-yoke hints Poke-Yoke
1.
Guide pin of
different
sizes
2.
Error detection
and alarms
3.
Limit switches
4.
Counters
5.
Checklists
Five best examples of avoiding human errors

Examples Poke-Yoke
IMATION 3M ENHANCED
PERFORMANCE
Floppy can be inserted only in the correct direction

Examples Poke-Yoke
Cannot be opened if the arrow is downwards

Examples Poke-Yoke
Chuck
Workpiece
Stopper
Before After

Examples Poke-Yoke
Wrong position
Correct position
Befor
e
Check station prevents incorrectly
positioned parts going into the
machine
After

Examples Poke-Yoke
Before
Products with short cables were
being accepted
After
Products with short cables cannot
be tested

Examples Poke-Yoke
Right Wrong
Before
Possible to reverse the polarities
After
Asymmetric shape ensures
correct orientation

Conclusion Poke-Yoke
Almost all mistakes can be prevented :
- if we take time to identify why they happen
- if we take steps to prevent them by using Poka-yoke
- if we introduce the safeguards and maintain