Hello all. I have a question today about poka-yokes. We are implementing a new joint assembly process, and one of the tools used in the assembly process has a groove on it that when inserted and twisted, locks into the part to be able to move it about until the assembly is done. Once done, the operator will untwist it and remove the tool. The discussion here is that this is a poka-yoke, but the question is whether or not this has to undergo annual verifications. Per our internal documentation, if it does not take a quantitative (attribute, go/no-go gauges) or qualitative (variable values) or is not referenced on a control plan/inspection plan as a means by which the quality of the product is ensured, then it does not need to be controlled by the gauge program. I wanted to ask here to see if anyone else has run into this question. To me personally, it seems like nothing more than a needed fixture for assembly. What are your thoughts?
Poka-yoke control
- Thread starter Jayfaas
- Start date
Good day @Jayfaas
May I ask as to what you are referencing when you refer to "annual verifications" ?
Thank you
Sounds as if you may be confusing measuring device with error proofing (poke-yoke). For implementation of error proofing, the requirement is that you identify it as a control on your control plan, including the frequency it is used...
(e.g. you have a machine that sorts dimes, and it has a feature that prevents a nickel from 'getting through", so once a "x" you run a fluorescent painted nickel through to ensure the machine is "catching" it. )
It's a process assurance control, not a measuring device.
Hope this helps.
Be well.
I think this is your question: but the question is whether or not this has to undergo annual verifications (we verify gauges annually that cannot be adjusted)
NO, I think.
this poka-yoke is something like fixture but not an adjustable gauge.
you can refer to TPM process (total productive maintenance)
NO, I think.
this poka-yoke is something like fixture but not an adjustable gauge.
you can refer to TPM process (total productive maintenance)
ChrisM
Quite Involved in Discussions
I would suggest that it does not require annual verification (what exactly is it verifying?) but it needs periodic (informal) inspection to make sure that it is undamaged and performing as intended; this could be something as simple as a visual check lasting a couple of seconds each time that it is to be used. I would hope that something similar exists for all jigs/tooling in use and that there is a system for reporting any anomaly that is noticed
As others have said there are many poke yoke devices that are not measurement controls. From error preventing to error reduction devices. These prevent or substantially reduce the ability to make an error. Measurement poke yokes tend to detect errors or defects after they have been created. Some examples are:
- Keyed parts so an assembly can only go in one way
- small parts bins sequenced so that similar looking/sized parts are assembled in the correct order
- bar coding of parts to avoid ‘typos’ in data entry or picking/use of the wrong part number
These like all controls and all processes should be validated as effective…(some standards and Customers require validation, some do not)
And like the use of PMs these devices should be verified as still intact, effective, etc. periodically or continually depending on the situation. Point of use ‘inspection’ is usually the best way of verification…
- Keyed parts so an assembly can only go in one way
- small parts bins sequenced so that similar looking/sized parts are assembled in the correct order
- bar coding of parts to avoid ‘typos’ in data entry or picking/use of the wrong part number
These like all controls and all processes should be validated as effective…(some standards and Customers require validation, some do not)
And like the use of PMs these devices should be verified as still intact, effective, etc. periodically or continually depending on the situation. Point of use ‘inspection’ is usually the best way of verification…
