An Honest Gauge R&R Analysis - Proposed usage of Donald Wheeler

MasterBB

Involved In Discussions
#1
Help with the proposed usage of Donald Wheeler.

The mathematical calculations/approach makes sense.

Questions:
How did you make the transition from the AIAG method to Wheeler's approach?
Any comments regarding the learning/training needed/convincing, etc.

If you actually continue using the AIAG approach; you actually maybe rejecting the results of a certain study; and hence you would seek to improve the Gage (Repeatability/Reproducibility); possible redesign of the gage. It becomes the manufacturere risk of doing so...

So, I am asking the experts: What is the consequences (if any) by not using the Wheeler's approach.

Thanks in advance.:thanks:
 
Elsmar Forum Sponsor

Bev D

Heretical Statistician
Staff member
Super Moderator
#2
Re: An Honest Gauge R&R Analysis

For most companies that I worked at I simply stopped using the approach detailed by AIAG (and others). When I worked in automotive, I would use wheeler's approach and for all decision making and submit the PPAP using that data but in the AIAG formulas. IF the answer using AIAG's approach was misleadign I usually talked directly to the quality rep. a lot of them fully understand the difference and were reasonable in their response.

the biggest consequence of using the AIAG published method is that your understanding of your measurement system will be very meager at best.
 

MasterBB

Involved In Discussions
#3
Re: An Honest Gauge R&R Analysis

Bev,

Thanks for the reply.
I have not used the Honest Approach. But thus far; have not had any issues utilizing/improving the gage used as a result.
In the other side, using Wheeler's approach; your window of acceptability just got wider. This maybe tricky to convince others to go that route.

What do you think Bev?

Thanks again.
 
M

mikefron

#5
Re: Need Help Understanding Gage R&R Results

Back when I went to undergrad engineering school (1960's dark ages) statistics was not a formal part of our curriculum. So, what I know about statistics has been self taught. Having worked for many years in automotive manufacturing engineering I have seen many Gage R&R calculations. It wasn't until I began reading this forum and papers by Don Wheeler that I realized most of what I was told about Gage R&R was just flat out wrong. I have downloaded and used your Honest Gage R&R spreadsheet, and it is darned impressive. Is there somewhere I can go to get a Gage R&R for dummies, plain english explanation of the meaning and implications of each of the graphs. In particular I would like to understand the values calculated in the GRR Report and the MSA and MSE spreadsheets tabs. It would be helpful to know the difference in appearance between good and bad gage capability. Any helpful guidance would be appreciated.
 

Miner

Forum Moderator
Staff member
Admin
#6
There is no file attached within this thread, but since you referred to MSA and MSE tabs, I am guessing that it is one of my files.

Take a few minutes and review my blog on MSA. I cover the traditional approach as well as Dr. Wheeler's. Then, if you have additional questions, you can ask them here.
 

Marc

Hunkered Down for the Duration with a Mask on...
Staff member
Admin
#7
Alan Miner's Measurement Systems Analysis (MSA) Article Series

Intro to Measurement System Analysis (MSA) of Continuous Data – Part 1: What and Why?
http://Elsmar.com/Forums/blog.php?b=124

Intro to Measurement System Analysis (MSA) of Continuous Data – Part 2: Bias
http://Elsmar.com/Forums/blog.php?b=125

Intro to Measurement System Analysis (MSA) of Continuous Data – Part 3: Linearity
http://Elsmar.com/Forums/blog.php?b=126

Intro to Measurement System Analysis (MSA) of Continuous Data – Part 4: Stability
http://Elsmar.com/Forums/blog.php?b=128

Intro to Measurement System Analysis (MSA) of Continuous Data – Part 5a: R&R
http://Elsmar.com/Forums/blog.php?b=130

Intro to Measurement System Analysis (MSA) of Continuous Data – Part 5b: R&R
http://Elsmar.com/Forums/blog.php?b=131

Intro to MSA of Continuous Data – Part 6: R&R for Non-Replicable Measurements
http://Elsmar.com/Forums/blog.php?b=132

Intro to MSA of Continuous Data – Part 7: R&R using Wheeler’s Honest Gage Study
http://Elsmar.com/Forums/blog.php?b=136

Intro to MSA of Continuous Data – Part 8: Comparison of Two Gages
http://Elsmar.com/Forums/blog.php?b=151

Intro to MSA of Continuous Data - Part 9: %Tolerance for One-sided Specs
http://Elsmar.com/Forums/blog.php?b=164

Intro to MSA of Continuous Data - Part 10: Creating gauge families
http://Elsmar.com/Forums/blog.php?b=170

Advanced MSA of Continuous Data - Part 1: Within Part Variation
http://Elsmar.com/Forums/blog.php?b=220
 
S

statdoug

#8
I would direct you, and anyone interested in MSA to the AT&T Statistical Quality Control Handbook section B-3, and I think Don Wheeler would agree as he has promoted this methodology for years. Chart the study. Forget about the summary statistics. This will show you what you really need to know from a Gage error study (if you are actually looking for understanding, and not just trying to meet a standard.)
 
M

mikefron

#9
Thanks Miner,

I apologize for the confusion. Yes, I was using your spreadsheet and I have tried to attach the workbook populated with my own data, but unfortunately, I have to post 5 times before I can attach a file (this is my second). As suggested, I have read through your blog and Dr Wheeler's papers. That helped tremendously, but I am still a little confused on interpretation of my gage study, and I would appreciate a little more explanation of the Tolerance Analysis on the Gage R&R report tab and the Gage Performance Curve tab.

My questions would be so much clearer if I could show you the spreadsheet, but we will probably have to go back and forth a few more times until I reach the magical 5 posts.

Gage Performance Curve: Can you put into words what each curve is telling me, especially Pa?

I have a manufacturing group trying to measure parts within 0.005 " total tolerance using a hand caliper. My part variation curve is off-center which would indicate the process isn't centered, which, in this case, I believe is deliberate. If the parts are too thick, they can be reworked, but undersized, and they are scrap.

Why is the Gage Error plot centered on the spec limits and not offset like the other two curves?

How do I interpret the Pa curve? A curve on the graph is the probability ... (please complete the sentence)

Gage R&R Report Tab:

Similar confusion. The two limits shown below the 99.90 probability... Is it saying that if I measure (read on the gage) values within that range there is a 99.90 probability the parts are actually within spec?

Thanks in advance for your help.

Mike
 

Miner

Forum Moderator
Staff member
Admin
#10
Gage Performance Curve: Can you put into words what each curve is telling me, especially Pa?

I have a manufacturing group trying to measure parts within 0.005 " total tolerance using a hand caliper. My part variation curve is off-center which would indicate the process isn't centered, which, in this case, I believe is deliberate. If the parts are too thick, they can be reworked, but undersized, and they are scrap.

Why is the Gage Error plot centered on the spec limits and not offset like the other two curves?

How do I interpret the Pa curve? A curve on the graph is the probability ... (please complete the sentence)
Pa is the probability of acceptance. The shape of curve is determined by the measurement variation. Your ability to know the true value of the part is clouded by the measurement variation. Far enough outside the specification and the probability that you accept a bad part is zero. Far enough inside the specification and the probability that you accept a good part is 100%. However, the closer that you get to the specification the probability that you will accept a good part drops as low as 50%. As you pass outside the specification, the probability that you will accept a bad part can be as high as 50% until you move far enough away from the specification.

The gage error curve was left centered because I viewed it as independent of the specs. Whereas that part variation and total observed variation (part plus gage error) was dependent on the specs.


Similar confusion. The two limits shown below the 99.90 probability... Is it saying that if I measure (read on the gage) values within that range there is a 99.90 probability the parts are actually within spec?
My memory is drawing a blank here. :eek: Once I see your attachment, I'll be able to help.
 
Thread starter Similar threads Forum Replies Date
B Wheeler Honest Gauge R&R macro wanted Excel .xls Spreadsheet Templates and Tools 2
W SAP QM Module - Honest assessment wanted Quality Assurance and Compliance Software Tools and Solutions 11
M Honest GR&R (Gage R&R) Tolerance Analysis Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 10
D Quality Digest article - "An Honest Gage R&R Study" - Where is he getting the d2*? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
Miner Intro to MSA of Continuous Data – Part 7: R&R using Wheeler’s Honest Gage Study Imported Legacy Blogs 17
Jim Wynne A brutally honest job seeker Coffee Break and Water Cooler Discussions 2
M Some people here at the Cove are often brutally honest - Dual/Secret Identities? Coffee Break and Water Cooler Discussions 43
C Gauge R&R Question Using Minitab Software 1
S Calibration Frequency for Slip Gauge Kit used for CMM Calibration? General Measurement Device and Calibration Topics 0
J Gauge Suggestion: Specialty or Custom General Measurement Device and Calibration Topics 1
F Calibrating Taper Sleev/Plug Gauge General Measurement Device and Calibration Topics 0
I How many gauges in a Go/No Go Gauge? General Measurement Device and Calibration Topics 7
J Standard used to determine if check fixture gauge is acceptable Reliability Analysis - Predictions, Testing and Standards 2
J Designing new gauge tracking software IATF 16949 - Automotive Quality Systems Standard 4
R Gauge R&R on pre-set torque wrench Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
C Aluminum galling on thread plug gauge Manufacturing and Related Processes 10
J Gauge R&R on a torque measurement Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 11
K I’m looking for a square probe for my linear height gauge Manufacturing and Related Processes 1
A Gauge Study for Small Lots Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
G Supplier Checking With Gauge Pin Problem Solving, Root Cause Fault and Failure Analysis 2
H Analog Pressure Gauge with no EN837 accuracy class information General Measurement Device and Calibration Topics 5
G Gauge R&R on multiple dimensions using 3D measurement system Capability, Accuracy and Stability - Processes, Machines, etc. 6
H Thread Plug Gauge Tolerances General Measurement Device and Calibration Topics 3
R Do Brands Matter When Purchasing Bore Gauge? General Measurement Device and Calibration Topics 2
D Using "Particle Size Standard" templates as gauges - How to avoid giving a gauge # while using for process control? General Measurement Device and Calibration Topics 2
D AS9100 Inspection records - Is there a requirement to have gauge ID and calibration status AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 5
G Comparing Gauge Blocks - Translating the calibration between the master set and the QA set General Measurement Device and Calibration Topics 2
F Gauge R&R & Calibration Intervals Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 14
Ron Rompen Source needed for Spline Form gauge (GO and NOGO members) General Measurement Device and Calibration Topics 3
S How to calculate the maximum allowable hysteresis of a pressure gauge General Measurement Device and Calibration Topics 1
S Gauge R and R - Product - Conveyor belt with threads that goes on Sprocket Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 10
R Feeler Gauge Calibration - What tolerance is used for calibrating feeler gauges? General Measurement Device and Calibration Topics 4
F Holes position inspection - Calculation of centre distance and plug sizes of a gauge Inspection, Prints (Drawings), Testing, Sampling and Related Topics 5
K Measurement Uncertainty Budget (MU) of for Ultrasonic Thickness gauge Measurement Uncertainty (MU) 1
R Radius Gauge R&R Study Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 10
A Calibration of Pressure Gauge, How to Determine Calibration Tolerance General Measurement Device and Calibration Topics 1
S Thread Ring Gauge verification General Measurement Device and Calibration Topics 6
G Uncertainty Budget Examples for Caliper, Micrometer and Dial Gauge Measurement Uncertainty (MU) 3
S Pressure Gauge Calibration Uncertainty Calibration and Metrology Software and Hardware 5
N Correct reading for analog pressure gauge ISO 17025 related Discussions 2
Ron Rompen Gauge Design Standards Inspection, Prints (Drawings), Testing, Sampling and Related Topics 2
B Gauge CAD certification to Part CAD vs. Gauge certification to Part CAD General Measurement Device and Calibration Topics 1
shimonv Feeler Gauge as a Medical Device Accessory EU Medical Device Regulations 3
C Proper Thickness Gauge for Foam/Felt and Soft Materials General Measurement Device and Calibration Topics 5
J What kind of Tool and Gauge in IATF 16949 Clause 8.5.1.6? IATF 16949 - Automotive Quality Systems Standard 1
alonFAI Gauge R&R for a Peel Tester (tensile tester) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 11
R Height gauge to measure short hard to access heights General Measurement Device and Calibration Topics 3
V Why Gauge R&R 10% is acceptable for variable instruments ? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
B Can we calibrate a standard pin with a gauge? General Measurement Device and Calibration Topics 2
C How to perform Gauge R & R on Automated Test & Measurement Equipment Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 8

Similar threads

Top Bottom