C
I have the folowing case :
the result from the GRR study is 16,66% . The NDC indicator shows 0,39 ! This was marked as a minor NC and the explaination was
TS16949 clause 7.6.1 states“... The analytical methods and acceptance criteria used shall conform to those in customer reference manuals on measurement systems analysis. Other analytical methods and acceptance criteria may be used if approved by the customer...”
· the report for Micrometer showed an NDC of 0.4 yet the system had been accepted with no investigation into this low figure.
My opinion is that if you use the 1:10 rule and your parts are almost perfect with insignificantly small part variance , the NDC is expected to be less than 5 , simply because it uses the formula PV/GRR. And tbh i can`t understand what is the relation between the text mentioned from the auditor and the observed situation.My customer don`t have any reference manual regarding the MSA requirements at all.And i doubt that the auditor use his brain at all .for example :
the nominal value is 3,35mm with tolerance +/- 0.05
the results obtained are:
3.331
3.335
3.332
3.334
3.337
and so on...
the machine producing this part is set to limits 3,3~3,4 mm
so if somebody can prove me that this tool is not good for this measurement task please hit me in the face.Any comments are welcome.
the result from the GRR study is 16,66% . The NDC indicator shows 0,39 ! This was marked as a minor NC and the explaination was
TS16949 clause 7.6.1 states“... The analytical methods and acceptance criteria used shall conform to those in customer reference manuals on measurement systems analysis. Other analytical methods and acceptance criteria may be used if approved by the customer...”
· the report for Micrometer showed an NDC of 0.4 yet the system had been accepted with no investigation into this low figure.
My opinion is that if you use the 1:10 rule and your parts are almost perfect with insignificantly small part variance , the NDC is expected to be less than 5 , simply because it uses the formula PV/GRR. And tbh i can`t understand what is the relation between the text mentioned from the auditor and the observed situation.My customer don`t have any reference manual regarding the MSA requirements at all.And i doubt that the auditor use his brain at all .for example :
the nominal value is 3,35mm with tolerance +/- 0.05
the results obtained are:
3.331
3.335
3.332
3.334
3.337
and so on...
the machine producing this part is set to limits 3,3~3,4 mm
so if somebody can prove me that this tool is not good for this measurement task please hit me in the face.Any comments are welcome.
