mercedes-benz produktionssystem quelle: lmc/kress mps-office trainingscenter mcg/p...

Mercedes-Benz Produktionssystem

Quelle: LMC/KressMPS-Office Trainingscenter MCG/PVuB_Jidoka_Poka_yoke.ppt; Stand: 031205

MPS-Verständnis und Bewußtsein, Experten/E4VuB Jidoka/Poka Yoke

Poka Yoke (jap.) :„prevention of careless unintentional errors“

.

Term:

Poka = Error,unintentional fault Yoke= prevention

Realisation of simple mechanisms for recognition and prevention of slips (lapses)and accordingly reaching the flawless target

Ziele:

"POKA-YOKE" : Term and Target

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Methods of Poka Yoke•controlling•Signalizing •Lines stop

Recognition of

errors(faults)

Prevention of error

development

Poka Yoke has two functions




1. forgetting

2. Misunderstandings

3. Mixing up

4. Missing training

5. On purpose

6. overseeing

7. slowlessness

8. Wrong standards

9. Unexpected effects

Liable causes of slips




• Missed working steps (process)

• treatment error

• error during insertion and attaching the workpieces

• missing parts

• defective parts

• application of the defective workpiece

• operation error

• setting error

• installation error

• insufficient preparation of tools and equipment

• ...

Types of errors(faults)

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physical Characteristics e.g.:- weight- Form- size- colour

Process characteristics e.g.:- Process sequence- part number- tool

Deviation from the previously defined sizes e.g.:- Production quantity- system condition- Methods- forces

Manual check Automatic check

Poka Yoke can recognize and prevent different errors ,either manually or automatically




examples

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• attaching(clamping) procedure (automatic error (fault) prevention)

Distance holder

Distance holder

pushes the work piece

Distance holder

workpiece

Checking tool• drill hole depth

(manual error recognition)

example I.O. N.I.O.

Checking tool does not

settle properly

Workpiece with a drill hole

Checking tool settles

properly

Example for physical characteristics

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examples O.k. Not O.k

• Addressing of the envelope

An Herrn MustermannMusterstraße 4

22222 Musterstadt

sonstwasfirma

Berlin 12.4.02 letter

Envelope with transparent window

An Herrn MustermannMusterstraße 4

22222 Musterstadt

Address of the letter appears from the transparent window

Address of the letter does not appear from the transparent windowNote: the Yoka poke transparent window assures that the address of the letter

paper coincides with the address of the letter envelope.,accordingly no wrong letter labels are possible. But of course it won‘t assure ,that the address on the letter paper is the right one.

• Form casting

Upper part fits the lower part

Upper part is rotated 180 degrees

Upper part with different drills

Lower parts with different guiding pins

Examples for process characteristics

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• Check list for quality essential points assurance

Checkliste1) Programm eingeben2) Maschine starten3) Teile auflegen4) schrittmodus wählen


All points are ticked

Not all the points are ticked

• Temperature indicator for quality relevant temp


Indicator in the green range

Indicator in the red range

Examples for previously defined sizes

example I.O. N.I.O.




Poka-Yoke in the daily life:

Floppy disc-drive in the Computer Electrical plug:




Pressing on the standing door at the line end through an equipment at the line

Error prevention(Poka Yoke) with a simple equipment




Example error prevention

Size of the gas opening avoids wrong tanking,attachment of the tank cover avoids forgetting




Beispiel Fehlervermeidung

light release prevents too early finish of a check station




.. During operating a system

Prevention of concurrent openingof different pipelines





Error prevention through

organizing (preparing)





summary

• ... processes are this way assured ,so that no defective part reaches the subsequent process (to the customer).

• ... requires and supports structural problem solution processes (causes analysis!) and increases the responsibilty consciousness of the workers.

• ... increases the production of the workers through the coupling of man-machine(e.g. prevention of maintenance on the machine)

• ....enables the quality to produce rather than check and accordingly solid processes are reached

Through Jidoka / Poka Yoke

mercedes-benz produktionssystem quelle: lmc/kress mps-office trainingscenter mcg/p...

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