sps0650en poka yoke
TRANSCRIPT
Faurecia Excellence System
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Group Quality Department
Quality System Efficiency
The 6 Quality Basics -> Poka Yoke
Purpose: Poka Yoke methodology
Scope: all production sites
FAU-S-PS-0650 / EN issue 01
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1 – Definition
A poka-yoke is a simple and reliable device that physically prevents:either the error leading to the defect or the transmission of the defect to the next workstation
Of course, not producing the defect in the first place is always preferable to detecting the defect afterwards. (An once of prevention is worth a pound of cure, as they say.)
There are two types of poka -yoke: Product: based on inherent product characteristics such as shape or symmetryProcess: based on certain product characteristics in order to avoid errors in the manufacturing process.
The poka-yoke must be permanent .
The poka-yoke must be “foolproof” (i.e. it must be impossible to bypass).
Only an authorized person (e.g. Gap Leader, Supervisor) may intervene.Situations to avoid: - reset button
- master key- simple disconnection (e.g.from electrical outlet)
The poka-yoke must be foreseen upstream, right from the product/process design phase.
Examples of poka-yokes in everyday life:3.5” diskettes can not be inserted upside down because one corner is cut. If the cut corner is on the wrong side, it hits something and the diskette will not go all the way in.In an ATM (cash dispenser), you have to remove your credit card before you can get your money. This prevents you from forgetting your card in the machine.
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2 - Examples
PRODUCT poka-yoke:
Example: guide pins of different shapes and/or sizes
PROCESS poka-yoke :
Example: poka-yokes are built into the process to check that an operation has been properly performed:
Without poka-yokes: defect possible (reversed assembly)
With poka-yokes: defect cannot be created
Screw-counter. If a screw is missing or there is insufficient torque, the part is prevented from moving on to the next workstation.
The conveyer stops automatically if the seat is in the wrong position for delivery (headrest too high).
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3 – Identification of Process Poka-Yoke
To improve identification and tracking of process poka-yokes, each one is given a reference number and represented on the plant layout diagram as shown:
FINAL INSPECTION
PKY 001
PKY 002
PKY ___
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4- Visual Management
This red symbol is PERMANENTLY fixed to the machine
Red means the poka-yoke is out of order.
The label shows the poka-yoke number and the parameter that must be inspected 100%.
The system must be repaired within 8 hours of the breakdown. If necessary, a spare parts stock is created.PARAMETER:
OUT OF ORDER100 % INSPECTION REQUIRED
PKY002
Green means the poka-yoke works properly.
Validation must take place before applying this symbol.
The label shows the poka-yoke number and the parameter that is under control.
PARAMETER:
WORKING
PKY002
This symbol must be visible and accessible to the operator, who is responsible for visual management
=ON PARAMETER :
IN ORDER
PKY002
No inspection of this characteristic
The poka-yoke works
The poka-yoke doesn’t work
= ON PARAMETER :
OUT OF ORDER100 % INSPECTION REQUIRED
PKY002
100 % Inspection
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5- Validation and capitalisation
Validation:
Each poka-yoke has a dedicated validation sheet :(FAU-F-PS-0222) specifying:parameter or critical characteristic validation method: master part (correctly identified), description of incorrect operation
It is the operator who validates poka-yokes:at each start-up: start of shift or after breakdown (see guide “OK 1st part")using validation sheet FAU-F-PS-0222
As soon as the operator sees a poka-yoke malfunction, s/he must immediately notify the Supervisor. The operator logs the time of the malfunction in order to organize an inspection of all the parts produced up to this point.
The operator must be trained to conduct 100% inspection of the parameter when the poka yoke fails.
Capitalisation:
Each poka-yoke has a definition sheet (FAU-F-PS-0221). This document is managed and updated by the UAP Quality correspondent and contains the following information:
Detection methodLocationExplanation of improvementsEffects and costs
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Appendix: suggestions for designing Poka-Yokes
Identify objects by characteristics such as:weightdimensionsshape
To detect operator deviation or errors, use devices:with physical contact (e.g. contactor, lever) without physical contact: photo-electric cells (transmission, reflection)
To detect deviation from set values, use measurement systems:pressure,temperatureelectricity (voltage,amperage)vibrationrpmdata transmission
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General Information
Author :Group QSE
Date : 12 January 2004
Aim of the modification:Complete revision of the previous version
Cancels and replaces:• FAU S PS 0220
Associated documents:• FAU S PS 0610• FAU S PS 0620• FAU S PS 0630• FAU S PS 0640• FAU S PS 0660• FAU F PS 0221• FAU F PS 0222