Attribute Gage R&R Form - Long Version - AIAG's MSA Manual

C

Coleman Donnelly

#11
I am a little new to the quality world but I am learning so bear with me as I display my ignorance on this topic...

We are a small to mid size single plant company that produces various steel sheet metal parts. We create attribute hand held gages and GD&T checking fixtures for all of the product that we produce. Our process does not allow us the luxary of creating the necessary range of product to satisfy the AIAG handbook guidelines for a gage R&R study. I have replaced the person that would have been responsible for this work so there is know real athority in house for me to receive any guidance from. The instruction that I have been give is to use 10 parts and with one of the 10 parts being bad and have 3 different operators try to find the bad part 3 times consecutively. This does not seem to coincide with the spirit of the process.

My proposal was to clamp the part onto the gage on the CMM and define with variable data the consistancy of the gage.

What are your thoughts on this??
 
Elsmar Forum Sponsor
J

justncredible

#12
Coleman, that is the most bizarre thing I have ever heard. There is GR&R for a attribute gage.

Attribute = go/no-go gages

Smack or fire whoever came up with the idea of trying to find the bad part in a pile of 10. Smack him with the AIAG MSA book, it is a paperback so it will only leave a red spot. Will be gone by the time the cops show up. :agree1:
 

Jim Wynne

Staff member
Admin
#14
Coleman, that is the most bizarre thing I have ever heard. There is GR&R for a attribute gage.

Attribute = go/no-go gages

Smack or fire whoever came up with the idea of trying to find the bad part in a pile of 10. Smack him with the AIAG MSA book, it is a paperback so it will only leave a red spot. Will be gone by the time the cops show up. :agree1:
But don't do the smacking with the AIAG MSA 2nd Edition, because it gave a "short method" that involved finding the bad parts in a "pile" of 20. :D
 

Jim Wynne

Staff member
Admin
#15
The instruction that I have been give is to use 10 parts and with one of the 10 parts being bad and have 3 different operators try to find the bad part 3 times consecutively. This does not seem to coincide with the spirit of the process.
Who told you to do this? If it wasn't the customer, you should talk it over with their quality people. Whenever the default requirements don't make sense in a given application, it's really important to establish a method the customer approves of, and to get the approval in writing. As I mentioned in another post in this thread, there's a "short method" in the 2nd Edition AIAG manual (now obsolete) that involves the type of study you're talking about, only with 20 parts. See the attachment.

My proposal was to clamp the part onto the gage on the CMM and define with variable data the consistancy of the gage.
This would be more on the order of calibration; it doesn't take operator influence into account.
 

Attachments

C

Coleman Donnelly

#16
This would be more on the order of calibration; it doesn't take operator influence into account.

I agree with this statement if you are aligning off of the part - I would intend to align off of the tooling balls or datum targets so that operator influence would be taken into account because my 0 points would not vary based on part position. I would also add the machine uncertainty to the result so that CMM bias does not allow us to pass when we should have failed...
 

Jim Wynne

Staff member
Admin
#17
I agree with this statement if you are aligning off of the part - I would intend to align off of the tooling balls or datum targets so that operator influence would be taken into account because my 0 points would not vary based on part position. I would also add the machine uncertainty to the result so that CMM bias does not allow us to pass when we should have failed...
I guess I don't understand the gage in question. Is it always used in conjunction with the CMM?? If it's a handheld go/no-go gage of some sort, you need to do the study with the operators who'll normally use the thing. Simply verifying that the gage is properly designed isn't MSA.
 
C

Coleman Donnelly

#18
My proposal would be to have the typical gage operator load and un load the parts onto a checking fixture that is on the CMM. After the part is loaded the CMM would go through an inspection routine to inspect the various call outs on the print. The CMM program would align off of the fixture itself not the part so operator influence would be taken into account. Typicaly the gage in question is not going to be used in conjction with the CMM the CMM is only being used to obtain variable data on how the part is positioned from one cycle to the next this way we can examine the variation of the gage "fixturing" the same part with 3 different operators 3 different times.

I would simply pull the T/P pins off of the fixture so that the CMM could measure the ACTUAL location of the circle rather that give me a pass fail result. This would result in Real Data that could be used with the Variable Gage R&R format as described in the AIAG handbook.

The argument that I am getting is that the variable data is irrelevent because the gage is not a variable gage.

My argument is that the purpose of the gage R&R process is to show a range of variation in your inspection process, not a range of variation in the characteristics of a gage pin. The easiest way that I can see facilitating data that expresses this variation in fixturing part position is with variable data because our process does not allow us to create the "Range of parts" necessary to comply with the method in the handbook - Does this make sense?
 

Jim Wynne

Staff member
Admin
#19
My proposal would be to have the typical gage operator load and un load the parts onto a checking fixture that is on the CMM. After the part is loaded the CMM would go through an inspection routine to inspect the various call outs on the print. The CMM program would align off of the fixture itself not the part so operator influence would be taken into account. Typicaly the gage in question is not going to be used in conjction with the CMM the CMM is only being used to obtain variable data on how the part is positioned from one cycle to the next this way we can examine the variation of the gage "fixturing" the same part with 3 different operators 3 different times.

I would simply pull the T/P pins off of the fixture so that the CMM could measure the ACTUAL location of the circle rather that give me a pass fail result. This would result in Real Data that could be used with the Variable Gage R&R format as described in the AIAG handbook.

The argument that I am getting is that the variable data is irrelevent because the gage is not a variable gage.

My argument is that the purpose of the gage R&R process is to show a range of variation in your inspection process, not a range of variation in the characteristics of a gage pin. The easiest way that I can see facilitating data that expresses this variation in fixturing part position is with variable data because our process does not allow us to create the "Range of parts" necessary to comply with the method in the handbook - Does this make sense?
Here's the deal: for attributes MSA, you need to demonstrate that the measurement system as it's used in production will always discriminate between conforming and nonconforming parts. The only statistically reliable way to do this is to have operators check parts that are known to be "good" and "bad" in sufficient numbers. Your problem, it seems to me, is not having enough parts to be able to arrive at a statistically sound conclusion. You need to approach this parsimoniously--don't make it more complicated than it needs to be. You need to do it with as many parts as you can, and you need to make sure that your customer understands the situation and approves.
 
J

justncredible

#20
Blah, I am not liking the office 07'.

Here are some sheets from a little birdie, I did not make them, and have no idea what birdie made them. These are not double checked by me as of yet.
 

Attachments

Thread starter Similar threads Forum Replies Date
S MSA for attribute relation gage Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
M Template for Attribute Gage R & R wanted Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 3
A Does an attribute study (Go/NoGo pin gage) need two studies (1 for each pin) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
B Attribute Gage R&R study according to "Charbonneau" Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
L Gage Blocks: Attribute or Variable Gage? General Measurement Device and Calibration Topics 3
D Calibration of a Width Gage Slot with an Attribute Gage - Maximum Width Condition General Measurement Device and Calibration Topics 16
D attribute gage RR in a unique way Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
M Proper Gauging - GD&T - Attribute gage to check true positioning on the shop floor Inspection, Prints (Drawings), Testing, Sampling and Related Topics 6
V Minitab - Attribute Gage Study Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
N Example of how to perform a Visual Attribute Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
K MINITAB 16 - Attribute gage study (Analytic method) and Gage R&R Study (Expanded) Using Minitab Software 2
J Minimum number of parts to do an attribute gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 8
A Minimum Number of Parts for Attribute (Go / NoGo) Data Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
N Survey about Attribute Gage and Sight Checking R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
kedarg6500 Gage R&R for Attribute Data - Pump Noise Test Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
G MSA Gage R&R and Attribute Forms Attached Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
L Correct Sample Size for Attribute Gage R&R (Good / Bad parts) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 12
D "GM Method" Gage R&R for Attribute Fixtures Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 3
A Destructive Attribute (Crossed) Gage R&R - Need Help! Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 3
O Destructive Attribute Gage R&R without LSL/USL Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
M Practicality of Metal Stamping Attribute GR&R (Gage R&R) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
M Attribute Gage MSA - What is the width of the gray area of ​​doubt? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
J GR&R (Gage R&R) Sample Setup for Attribute Inspection Gages Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
Hami812 Attribute Data Gage R&R - Managing Data Sets - Minitab Using Minitab Software 2
J Gage R&R Study by Attribute (ACCEPT-REJECT-INVESTIGATE) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
B Attribute GR&R (Gage R&R) using a CMM (Coordinate Measuring Machine)? General Measurement Device and Calibration Topics 3
L Tools in Gage R&R - Acceptability of an Attribute Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
B Visual Inspection (Attribute Data) Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 27
J Attribute GRR (Gage R&R) - How to get Kappa Software Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
J Attribute Gage Studies - What gages are required to have Measurement Systems Analysis IATF 16949 - Automotive Quality Systems Standard 4
M Procedure for Attribute R&R Gage Study?? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
R Destructive Attribute Gage Studies - inserted/pressed in parts Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
H Known non-conforming samples in attribute GR&R (Gage R&R) Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 3
S Attribute GR&R (Gage R&R) Studies for Metal Stampers Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 12
M Attribute Gage R&R on Torque Wrench Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
R Percent defective in Attribute GR&R (Gage R&R) General Measurement Device and Calibration Topics 3
S Attribute Gage R&R - Automated Test Equipment Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
R Attribute Gage R&R analysis - Automated test system Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
C How to Determine Attribute Gage Uncertainty Measurement Uncertainty (MU) 1
R Attribute GR&R (Gage R&R) for Continuous Processes Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 3
J Gage R&R on Attribute Data Using Minitab 14 - Data from Automated Test Systems Quality Tools, Improvement and Analysis 2
H Attribute Data Gage R&R - Queries of data from a system Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 19
K Gage R&R on a special go/no-go attribute gage Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
P Attribute Gage Study using MiniTab Using Minitab Software 2
T Wind Turbine Blade Attribute Gage R&R Study Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 3
G Customer is requesting Variable Data for Attribute Gages in Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
R MSA Attribute gage repeatability and reproducibility IATF 16949 - Automotive Quality Systems Standard 1
J Audit Finding for this section - Min and Max for measurements - Attribute Gage Inspection, Prints (Drawings), Testing, Sampling and Related Topics 7
M Excel .xls Template for Attribute Gage R&R with ORDINAL Data needed Excel .xls Spreadsheet Templates and Tools 10
T Gage R&R Yearly Frequency Acceptance - Attribute gages - ISO/TS 16949 Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4

Similar threads

Top Bottom