Can GR&R (Gage R&R) be done between two machines

S

samuelP

#1
I have conducted a GR&R which the appraiser (A.V) is to monitor the reproducibility between two machines instead of two operators.
The result was very disappointing whereby I get the %GRR of ~50%.
Could anyone tell me what's wrong with the %GRR?
Or is it owing to my GRR procedure?

Note: The two machines are the same model puting adjacent/ side by side to one another.

Any advice is so much appreciated!!
 
Elsmar Forum Sponsor
P

prototyper

#2
Did you run the same parts through both machines?
How did you select the parts to check?
If you post the data someone may be able to help further.
 

Miner

Forum Moderator
Staff member
Admin
#3
Moved to MSA forum.

Yes you can use two machines as Appraisers, IF the machines are automated and there is no Appraiser impact. Otherwise, it is more appropriate to use a Youden Plot (aka Iso-Plot) to analyze two different measurement devices.

As to your question regarding why you have a high %GRR, you will have to attach the results at a minimum and preferably the data also. Otherwise, we would be guessing blindly.
 
S

samuelP

#4
yes. The same parts were run through both machines, whereby N=5
The parts are selected randomly. (with some ladder patterns)

This is the result of GRR:
Study Var % Study Var
Source StdDev(SD) (6*SD) (%SV)
Total Gage R&R 10.2431 61.459 57.51
Repeatability 3.7307 22.384 20.95
Reproducibility 9.5396 57.238 53.56
mc 6.4750 38.850 36.36
m/c*Disk 7.0056 42.034 39.33
Part-to-Part 14.5697 87.418 81.81
Total Variation 17.8101 106.860 100.00
ndc=2

Both machines is not fully automated. The appraiser impact comes in during the loading of specimen onto the platform of measurement. However, the measurement process other than load/unload part is done by the machine.

So in this case, can I say that using a Youden-plot is more appropriate?
 

Miner

Forum Moderator
Staff member
Admin
#5
If there is any possibility that the manual loading of the machines could affect the results (from variation in placement of the parts) you should either run separate MSA's with a Youden plot to check the machine to machine differences; or add operator to the existing design and analyze the results using a 3-way ANOVA with some supplemental manual calculations instead of the canned Gage R&R routine.

The drivers of variation in your data are:

  1. Machine to machine differences_54%
  2. m/c * disk interaction_________39%
  3. mc_________________________36%
Does m/c and mc stand for machine? Also, what do you mean by ladder patterns?

Note: It would also be helpful to see the graphs and the rest of the data (as an attachment please after you have 5 posts, the scrambled text is difficult to interpret)
 
S

samuelP

#8
>Yes. Both mc and m/c stand for machine. (Sorry for confusion)
>The ladder samples mean the samples have a ascending count from sample1 to sample5
>The machine is a measurement machine using the laser source to detect the count which is invisible under naked eye

Can you explain why 3 way ANOVA is more suitable to monitor the difference between machine A & machine B instead of using a 2 way ANOVA?
As for Youden plot, would you mind explain further? As I am not familiar with the application of Youden plot.

Thanks...
 

Caster

An Early Cover
Trusted Information Resource
#10
The same parts were run through both machines, whereby N=5
The parts are selected randomly. (with some ladder patterns)


Were the parts very similar to each other (minimal part to part variation)?

Is the part variation very close to what the gage can detect (can not use the 1/10 rule)?

This will cause poor GRR results.

The less variation you have (from a good process) and the closer the tolerance is to what a World Class gage can measure, the worse the GRR will be.

There are no easy answers (except develop a better gage), it is the price you pay for getting good.

In my experience, this is very difficult to explain to a customer who is just looking for the magic less than 10% number.
 
Last edited by a moderator:
Thread starter Similar threads Forum Replies Date
M Has anyone done a Gage R&R for Spectrophotometer? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 10
I Gage R&R - Can GR&R be done on a representative sample from my tools fleet? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
S Should we check the normality of measurements when the calculation of Gage RR is done Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
T Plug Gage Calibration Calibration and Metrology Software and Hardware 1
L Gage R&R TMV Acceptance Criteria Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
S MSA for attribute relation gage Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
E Zero part to part variation - Gage R&R project Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 15
M Gage R&R and right way to measure Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 16
L Gage RandR on automated equipment. IATF 16949 - Automotive Quality Systems Standard 7
B Gage calibration frequency, ISO and IATF - What are the requirements Calibration Frequency (Interval) 3
D Difference between Test Method Validation and Gage R&R Qualification and Validation (including 21 CFR Part 11) 18
R Determining Uncertainty from Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
C Correct Calibration Method for Dial Depth Gage General Measurement Device and Calibration Topics 6
C Gage Block Wringing General Measurement Device and Calibration Topics 3
B Gage R&R with NDC=1 Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 19
S Type 1 Gage R&R or something else? Reliability Analysis - Predictions, Testing and Standards 6
G Should I perform Gage R&R only at the beginning of a new project? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
V Thread Plug Gage Pitch GO Diameter out of spec AQL - Acceptable Quality Level 8
G Gage R&R - Where am I going wrong? Part of a FAIR submission (Aerospace) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
R Gage R&R Excel templates Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 3
K Gage R&R with more than 3 appraisers Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
Anerol C Gage R&R Template AIAG 4th Edition IATF 16949 - Automotive Quality Systems Standard 3
T Attributes SPC study - Attributive control (Go gage) Statistical Analysis Tools, Techniques and SPC 5
S Capability or Gage R&R Study for Leak Tester? Reliability Analysis - Predictions, Testing and Standards 15
N % Tolerance - Type 1 study on the gages, then a gage R&R (ANOVA) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
M Definitive answer on Type 1 vs Type 2 vs Type 3 Gage Study Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 0
V Gage Management and Gage R&R Software General Measurement Device and Calibration Topics 1
D Gage R&R Study on Load Cells - Large chemical blending tanks IATF 16949 - Automotive Quality Systems Standard 1
B Minitab Type 1 Gage Study on True Position Question Measurement Uncertainty (MU) 1
S Gage R&R on alloy Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 10
8 Need Help - Runout - Function Gage Inspection, Prints (Drawings), Testing, Sampling and Related Topics 7
L Gage R&R studies for identical Devices - Need to confirm the requirement to perform them Reliability Analysis - Predictions, Testing and Standards 2
G Stab Pin Size For Check Gage Inspection, Prints (Drawings), Testing, Sampling and Related Topics 3
E Functional Gage for TOP applied at RFS Design and Development of Products and Processes 5
F No reproducibility Error in Gage R&R? Reliability Analysis - Predictions, Testing and Standards 4
M Template for Attribute Gage R & R wanted Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 3
G Warning about Deltronic Gage Pins - The "Certification of Accuracy" document General Measurement Device and Calibration Topics 13
A Gage type 1 study on CMM Capability, Accuracy and Stability - Processes, Machines, etc. 2
Q Gage R&R for Instant Measurement Machine Manufacturing and Related Processes 6
M Gage R&R with large inter part variance - Torque Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 7
D Do we need normal data for gage r&r studies? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
D Do I need part variation while doing Destructive Variable Gage R&R MSA study Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 19
S Gage R&R Standard Deviations Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
J Informational Gage R&R: Swapping operators Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
S Gage R & R for large amount of inspections IATF 16949 - Automotive Quality Systems Standard 10
S Ring Gage Thermal Expansion General Measurement Device and Calibration Topics 4
L Gage R&R for test precision or uncertainty prediction? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
S Minor diameter of threaded ring gage General Measurement Device and Calibration Topics 1
A Does Torque Gage Need Validation? Reliability Analysis - Predictions, Testing and Standards 4
J Ignoring a Failed Gage R&R and upcoming external audit IATF 16949 - Automotive Quality Systems Standard 22

Similar threads

Top Bottom