Acceptable Gage R&R - What is acceptable %error for Gage R&R

I am interedted in finding out what and acceptable %error is for Gage R&R? Is it different for different industries? Should it alowasy be targeted at a certain %? How is that determined by any of your companies?

Thanks, Jim Jakosh........Grand Rapids, Mi

If you are automotive you could use the ranges outlined in the PPAP manual,

10%
20%
30%

and continuously try to reduce the R&R as continuous improvement projects.

I know of no steadfast rules per se, just that a large part of the decision is based on the, specifications, operator experience, customer requirements, part use etc...

Any MSA gurus that can help me out here?

According to the manual:
Upto 10% of "Study Variation" : Acceptable
10-30%: Acceptable on the basis of usage/criticality of measurement etc.
>30% : Not acceptable


However, you could also compare with:
1. 'Total Tolerance' on the dimesion under study: If process capability is very good, GRR may actually turn out unaceptable as % of Study variation, but may be negligible as compared to tolerance. and
2. 'Process Variation' on the dimension being measured. This can be obtained from your SPC studies.

I am not sure if 10-30 rule should also apply to these two comparisons.

Atul, Niether am I!