Date post: | 18-Jan-2015 |
Category: |
Documents |
Upload: | jagjitsingh25 |
View: | 20,586 times |
Download: | 10 times |
Presented by:
Abhilasha Singh
Bhushan Salunke
Chetan Shah
Chanchal Gupta
Ruchi Shukla
Jagjit Singh Panesar
CONTENTS
INTRODUCTION
WHAT IS ERROR ?
POKA YOKE OVER ERRORS
IMPORTANCE
WHEN TO USE
HOW TO USE
METHODS
DAY 2 DAY EXAMPLES
2
NO
WHAT IS POKA YOKE ???3
a) Brother of PIKACHU
b) A new Chinese action hero
c) A diseaseIt’s a mistake proofing technique used by each of us
Pronunciation POH-KAH-YOH-KAY
YOKERU Avoid
POKA Mistakes
Coined in Japan during the 1960s by
as part of the Toyota Production System
INTRODUCTION4
Shigeo Shingo
Initially ‘BAKA-YOKE’ ‘fool-
proofing’
Dishonorable and offensive
Changed to ‘POKA-YOKE’ ‘mistake-
proofing’
5
INTRODUCTION (Cont.)
WHAT IS ERROR ???
A mistake : deviation from what is correct, right, or true
How to prevent error
Old way Scold peopleRetrain them Tell them to be more careful…
New way Training and motivationEasy way to do a job
The potential for human error can be dramatically reduced
6
What Causes Defects?
Errors lead to defects
1. Poor procedures or standards
2. Machines
3. Non-conforming material
4. Worn tooling
5. Human Mistakes
7
8
Help operators avoid mistakes in their work caused by
choosing the wrong part, leaving out a part, installing a part
backwards, etc.
Involves the implementation of fail-safe ways methods that
detect or prevent human and machine error at or near the
source.
Provides instant feedback and prevention of quality problems
9
Poka Yoke over Errors
10
Poka-Yoke as a…
Poka Yoke as Prevention Device:
Examples: part locators, part present sensors.
Poka Yoke as Detection Device:
Examples: vision system, limit sensors
11
12
Why is it important?
Helps people and processes
Refers to techniques that make it impossible to
make mistakes.
Helps drive defects out of products and processes
and substantially improve quality and reliability.
Thought of as an extension of FMEA.
13
Contd…
Used to fine tune improvements and process
designs from six-sigma.
Use the ideas and methods in product and
process design which can eliminate both human
and mechanical errors.
When to use it?
It is a technique, a tool that can be applied to any
type of process be it in manufacturing or the
service industry.
Poka-yoke can be used wherever something can
go wrong or an error can be made.
14
Contd…
Errors can be of any type-
i. Processing Error: Process operation missed or not performed per the SOP.
ii. Setup Error: Using the wrong tooling or setting machine adjustments incorrectly.
iii. Missing Part: Not all parts included in the assembly, welding, or other processes.
iv. Improper part/item: Wrong part used in the process.
v. Operations Error: Carrying out an operation incorrectly; having the incorrect version of the specification.
vi. Measurement Error: Errors in machine adjustment, test measurement or dimensions of a part coming in from a supplier.
15
How to use it?
Step by step process in applying poka-yoke:
1. Identify the operation or process
2. Analyze the 5-Ws and understand the ways a process can
fail.
3. Decide the right Poka-yoke approach, such as using a,
Shut out Type: Preventing an error being made, or an
Attention Type: Highlighting that an error has been
made.
16
Contd…
4. Determine whether a
Contact Method
Constant Number or Counting Method
Motion-Sequence Method
5. Trial the method and see if it works.
6. Train the operator, review performance and
measure success.
17
Methods in Detail
Contact Methods:-
“Do not have to be high tech!”
These can be as simple as blocks that do not allow parts to be seated in the wrong position prior to processing.
18
Methods in Detail
Take advantage of parts designed with an uneven shape.
This method signals to the operator right away that the part is not in proper position.
19
Methods in Detail
Constant Number or Counting Method:-
Used when a fixed number of operations are required within a process.
When a product has a fixed number of parts that are attached to it.
A sensor counts the number of times a part is used or a process is completed and releases the part only when the right count is reached.
20
Methods in Detail
Motion-Sequence Method:-
The third poka yoke method uses sensors to determine if a motion or a step in a process has occurred.
If the step has not occurred or has occurred out of sequence, the sensor signals a timer or other device to stop the machine and signal the operator.
21
Day 2 Day Examples of Poka-Yoke
22
Disk
23
File cabinets, opening one drawer locks all the rest,
reducing the chance of the file cabinet tipping.
24
Sinks
25
Microwaves
Washing machines
Central locking in modern cars
Key locks in mobiles
Refrigerators
Beeps in automobiles if key is left in ignition
26
Okay, So This Is Not An Everyday Example For
Anybody. I Hope You'll Find It Interesting …
27
Submarine
The bathyscaph is a deep water submarine used to explore the very lowest parts of the ocean. It is electrically powered. Once at the bottom, if the batteries or electrical system fail the best outcome would be for the sub to return to the surface. The designers made this outcome occur by holding the ballast in place with electromagnets. When power is lost, the ballast drops off automatically and the sub starts its ascent.
28
Characteristics of PokaYoke devices
Simple and cheap
Part of the process, permitting 100% inspection
Placed close to where the mistakes occur,
providing quick feedback
Designed to stop a particular mistake
A detection device cannot provide a complete
error proof solution
29
30
TO ERR IS HUMAN NATURE
BUT
INTELLIGENCE IS ALSO HUMANNATURE
SO
NEVER STOP FINDING WAYS OFNOT MAKING MISTAKES
REMEMBER
Thanks For Keeping Patience
31