%GRR was between 10-30% so we have to have a "backup plan" per auditor

kenb

Starting to get Involved
#1
During our Stage 1 audit the auditor said that if our %GRR was between 10-30% we have to have a "backup plan", but we cannot find anything in the IATF or ISO standards to support this. Could this be just a recommendation or is there something to it? Thanks.
 
Elsmar Forum Sponsor

Miner

Forum Moderator
Staff member
Admin
#2
Full disclosure: My automotive experience pre-dates IATF 16949, but I do consider myself knowledgeable in MSA. I recommend challenging your auditor on this. The usual terminology used for the 10-30% range is that the gage MAY be acceptable depending on the application, the cost of the measurement device, etc. There are a number of reasons that you can use to justify using a gage in this range:
  • Is the feature/dimension a significant/critical/CTQ characteristic? If no, the gage may be used.
  • Is the gage the state of the art? If yes, the gage may be used.
  • Is the next better gage extremely expensive? If yes...
  • ...
I would add these criteria (or those relevant to your business) to your procedure/documentation for MSA.
 

Jim Wynne

Staff member
Admin
#3
I second Miner's advice, FWIW. I'm curious, though, as to the form your auditor's advice was delivered in. Was this a verbal observation or was it cited as a nonconformity? Why did you not ask the auditor to explain?
 

kenb

Starting to get Involved
#4
Full disclosure: My automotive experience pre-dates IATF 16949, but I do consider myself knowledgeable in MSA. I recommend challenging your auditor on this. The usual terminology used for the 10-30% range is that the gage MAY be acceptable depending on the application, the cost of the measurement device, etc. There are a number of reasons that you can use to justify using a gage in this range:
  • Is the feature/dimension a significant/critical/CTQ characteristic? If no, the gage may be used.
  • Is the gage the state of the art? If yes, the gage may be used.
  • Is the next better gage extremely expensive? If yes...
  • ...
I would add these criteria (or those relevant to your business) to your procedure/documentation for MSA.
Yes, it is significant for some characteristics. Several tests are "quick and dirty" and widely accepted in our industry but very old. I don't think there is a better gauge for those tests other than similar ones to what we already have.
 

kenb

Starting to get Involved
#5
I second Miner's advice, FWIW. I'm curious, though, as to the form your auditor's advice was delivered in. Was this a verbal observation or was it cited as a nonconformity? Why did you not ask the auditor to explain?
Great questions. It was one of those verbal "I can't consult, but..." discussions. We did ask him to explain and he said it was in the MSA bluebook. I haven't read the bluebook cover to cover, but I don't recall ever seeing it in there.
 

Miner

Forum Moderator
Staff member
Admin
#6
You may have an argument based on state of the art, but I would be cautious since you said that they were very old. There might be newer gages available in other industries that might be adapted to yours. I used to work in the rubber industry, and they were extremely slow to adopt new technologies, even when it was only moderately expensive. Regardless, I would still recommend pushing back. An auditor cannot make a blanket statement such as you cited. They must cite objective evidence of the passage that you do not meet. The reason you do not recall having seen it is because it is not there. Ask him to cite the page and paragraph.
 

Ashland78

Starting to get Involved
#7
During our Stage 1 audit the auditor said that if our %GRR was between 10-30% we have to have a "backup plan", but we cannot find anything in the IATF or ISO standards to support this. Could this be just a recommendation or is there something to it? Thanks.
Hi Ken, it is in the 4th Edition, MSA book, that correlates with IATF. I think it can be as simple as the customer ok'ing the %. Hope that helps.
 

kenb

Starting to get Involved
#9
Miner - Most of the old gages are basically wet chemistry tests for our specific industry that involve balances, ovens, etc. There really aren't substitutions for the ones I'm asking about.

Ashland 78 - I know <10% is better, but is there somewhere it is stated that we need to have a backup? We never had a customer question anything less than 30% and only have a handful of IATF customers.

kbg1000 - we have very few CSR and that is not one of them, fortunately.
 

Miner

Forum Moderator
Staff member
Admin
#10
These are the relevant sections of the MSA 4th edition manual. Your auditor MAY be referring to page 128 below, but if they are, they are reading way too much into it. Note: The caution on page 78 means that you should also take the interpretation of the graphical results into account as well as the numerical.

1588625259451.png 1588625271144.png
 
Thread starter Similar threads Forum Replies Date
R New to MSA - I was told to use ANOVA for the GRR's Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
A Cg, Cgk and GRR of a CMM Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
L GRR for a tolerance that has changed Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
V Minitab GRR crossed Xbar and r method macro needed Using Minitab Software 9
T GRR based on part tolerance or process variation. Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 7
A Minitab 18: How to automate GRR Summary Table save Reliability Analysis - Predictions, Testing and Standards 1
J Question on very low NDC number with tolerable GRR ratio's Capability, Accuracy and Stability - Processes, Machines, etc. 7
C Evaluating GRR Scores %Tol vs %TV Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 9
S GRR on ID with set of pin gauges Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
Q What does % study variation of 20% mean in GRR? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 17
C %GRR <10% not possible. How to get approval by auditor? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 15
V GRR Study on a Finished Product - Batch Manufacturing Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
S Script of R software to conduct Nested GRR for Destructive Testing Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 0
A Hypothesis test for Bias, not for GRR. WHY ?? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
B How to perform a MSA - GRR (Gage R&R) A&R/ANOVA Vs GUM/VDA Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
J Calculating part variation from historic data for GRR study Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
S GRR (Gage Repeatability and Reproducibility) for Material Strength Tester Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
P New Part - How to choose what needs GRR (Gage R&R) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
K The basics of GRR (Gage R&R) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
A Need MSA %GRR Interpretation Advice Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
M GRR approach for off line Measuring Equipment Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
P Does anyone have the GRR Formula? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
5 Reasonable GRR result for a 0-1" micrometer with a total tolerance of .002" Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 16
T MSA - Should I compare my GRR to tolerance or to my sample? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 16
D What the impact is of a high %GRR/TV Capability, Accuracy and Stability - Processes, Machines, etc. 6
V Sample Range for a valid GRR using ANOVA in Minitab Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
F GRR (Gage R&R) with Different Scales Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 10
J Type 1 GRR (Gage R&R) on a One Sided Specification Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
J Analysis of GRR studies, MSA 4th Ed, Chapter III section B - Rigid Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
S Strange PT Ratio on an Excel spreadsheet for variable GRR ANOVA Method Excel .xls Spreadsheet Templates and Tools 2
A Customer Demands (MSA=Bias + GRR/2). Can somebody explain what it means? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
R ndc=0 and GRR=14% ??? Interpretation - basic question Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 9
I Minitab ANOVA Gage R&R Error (vs. EXCEL ANOVA GRR Calculation) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
R MSA - GRR (Gage R&R) Requirement for CMM Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 21
Rameshwar25 What is the significance of Spread in Calculating GRR (Gage R&R)? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
Rameshwar25 GRR (Gage R&R) Nested Anova Method Example Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 40
J CMM MSA - Can you use 1 GRR to satisfy requirement for all Key Features? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 11
M Minitab Type 1 Repeatability & GRR% of Tolerance Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
M Cp calculation on page 193 of the MSA 3rd edition May 2003 with %GRR Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
T When is GRR (Gage R&R) required? AIAG MSA Manual Version 4 Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 19
H GRR (Gage R&R) Study for Digital Temperature Gauge Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
L %GRR/TV or /TW for GRR of One Sided Specification - Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
S Gage R&R (GRR) Study - Please comment on the results Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 7
J Attribute GRR (Gage R&R) - How to get Kappa Software Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
S p-Value(s) for Anova (Crossed) GRR (Gage R&R) Studies Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 7
D GRR (Gage R&R) procedure for Mitutoyo Digital Micrometer wanted Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
T % Gage R&R Calculation - 100x(GRR/ (Spec/6)) or 100x(GRR/TV) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 20
O The Basis of %GRR (% Gage R&R) and other Statistics - Minitab Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 21
A Effect of %GRR (% Gage R&R) on Cpk Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 13
F GRR (Gage R&R aka GR&R) on Laser Gages for Plastic Extrusion Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 11

Similar threads

Top Bottom