Visual Inspection of a Weld - MSA (Measurement System Analysis)

[automoto]

Control plan state visual checking of weld. There are instructions (pictures) at workplace that explain which weld is OK and which is NOT OK. 3rd party auditor asks me if we perform MSA for mentioned case. Until now we did not conduct MSA for visual inspection. Does anyone have experiences wit that? What are your practices?

Aleš

 

[bobdoering]

Re: MSA for visual inspection

We do it with welds. It is a reasonable request - your gage is your visual criteria (charts, samples, etc.), and you perform an attribute study on a series of specimens to determine that all levels of skill inspectors pick the correct category (pass or fail) for the specimens you provide.

 

[wweng7]

MSA for visual inspection

--------------------------------------------------------------------------------

We do it with welds. It is a reasonable request - your gage is your visual criteria (charts, samples, etc.), and you perform an attribute study on a series of specimens to determine that all levels of skill inspectors pick the correct category (pass or fail) for the specimens you provide.

Can you attach some samples of this type of study?
Thanks in advance

 

[automoto]

Re: MSA for visual inspection

We do it with welds. It is a reasonable request - your gage is your visual criteria (charts, samples, etc.), and you perform an attribute study on a series of specimens to determine that all levels of skill inspectors pick the correct category (pass or fail) for the specimens you provide.

Reference manual state on page 125 "Visual standards may result in five to seven distinct categories. The analyzes described in the proceeding chapter cannot be used to evaluate such system"

Therefor could you explain how to perform attribute MSA for visual inspection of weld. Which method shall I use. Could you attach an example...

Thanks in advanced.

 

[bobdoering]

Re: MSA for visual inspection

Reference manual state on page 125 "Visual standards may result in five to seven distinct categories. The analyzes described in the proceeding chapter cannot be used to evaluate such system"

Therefor could you explain how to perform attribute MSA for visual inspection of weld. Which method shall I use. Could you attach an example...

Be sure to understand that it is true that if you are trying to categorize your product into separate visual criteria categories, that you can not use Section C to verify that you are getting all of the specimens into the correct categories (even worse if you have more than one reject condition possible per part.)

BUT - you can use it if you are using the visual standards to determine pass/fail specifically. Chances are, the bottom line of your visual criteria is pass/fail (any one or more conditions on the part is "fail") as far as the ultimate point of the inspection. The Section C layout would be adequate for such an MSA.