Definition Poka-Yoke - Definition - How do you define Poka-Yoke?

[wdavenportIII]

This is my first post, so hello to everyone. Now, for my semi-stupid question:

How do you define Poka-Yoke??

My company relates Poka-Yoke strictly to defect prevention. But I have text books that count defect detection as poka-yoke. I am preparing a presentation about my facilities efforts pertaining to PY and have counted both defect prevention and detection as PY. This will surely cause quite a bit of debate during the meeting.

Thoughts?

 

[bobdoering]

Re: Poka-Yoke Question.

This is my first post, so hello to everyone. Now, for my semi-stupid question:

How do you define Poka-Yoke??

My company relates Poka-Yoke strictly to defect prevention. But I have text books that count defect detection as poka-yoke. I am preparing a presentation about my facilities efforts pertaining to PY and have counted both defect prevention and detection as PY. This will surely cause quite a bit of debate during the meeting.

Thoughts?

True Poka Yoke to me is prevention - does not permit a bad part to be made. It may detect a bad subcomponent from trying to enter a process, or a part entering a process incorrectly - but will not permit it to be processed.

If you process a bad part, then do automated 100% inspection on it, it is not a poka yoke....except for - perhaps - the next operation....but that is a weak definition.

Let's see if anyone agrees....

 

[Marc]

Re: Poka-Yoke Question.

Also see: Error Proofing.

 

[Stijloor]

Also, look at this site: John Grout's Poka Yoke.

Stijloor.

 

[bobdoering]

Also, look at this site: John Grout's Poka Yoke.

That was some interesting confusion between ZQC and SPC. These guys are thinking too hard. Use ZQC to make sure a part is loaded into the machine and check and that the tool is not broken; use SPC to determine that the machine needs adjusted. Whew! Right tool for the job... SPC to maintain the same defect level and not preventive? Only if it is not used correctly...maybe for attribute stuff - such as the ZQC targets.

 

[Marc]

John Grout's Poka Yoke page

Also, look at this site: John Grout's Poka Yoke.

Stijloor.

A long time Classic. Thanks for linking.

 

[Miner]

Stijloor's link is an excellent site. The definitive source is from Shigeo Shingo himself in Zero Quality Control: Source Inspection and the Poka-Yoke System (Productivity Press, 1986).

Shigeo defined two high level types:

• Error proofing, which is done in the design to prevent errors. Examples include designed in features that make miss-assembly impossible.
• Mistake-proofing, which is done in manufacturing to:
  • Detect defects coming into the station
  • Prevent mistakes from occurring in the operation thus preventing defects
  • Detect mistakes as they occur before a defect is created
  • Detect defects as they occur and prevent them from leaving the station

So, mistake proofing is really both prevention and detection.

 

[wmarhel]

Poke-Yoke originally evolved from the term Baka-Yoke. Baka in Japanese means stupid. It didn't evolve into Poke-Yoke until a woman took issue with Ohno himself about being considered stupid.

Its the angry woman thing I guess....

Wayne

 

[bobdoering]

Re: Poka-Yoke Question.

Let's see if anyone agrees....

Figures Shigeo wouldn't agree....

 

[reynald]

I personally define poka yoke as any device or system that detects or prevents any errors from/when happening with the end goal that it prevents those mistakes from being translated into defects.

From this i consider control charting as a potential poka yoke, but only if you control chart the key process INPUT variables. If i detect early on that there is something wrong with my inputs, i could stop the process and prevent my output from being defective. That for me is an effective poka yoke.

But anyways that was just my

Reynald