Gage R&R Form - Excel or other - Calculations Questions

Hi,

Has someone a R&R file ( Excel or any other format ) avaible in order to send it me?

Regards

I have one in spanish languaje, is it useful for you?

Arte:

R&R form

Of course,

thank you Arte, please send it me.

here there is, sheet one is completely filled, and sheet 2 is to fill in the blank.

Regards

Arte:thedeal:

Thanks

Dear Arte,

thank you very much.

Gracias

K2 in GRR Form

Hi,
In the GRR form, K2 is the constant used to calculate reproducibility,

reproducibility(raw)= (5.15*people variance)/d2

For 2 appraisers, d2 is 1.41,

May I know where does 1.41 come from?

Thank you very much.

Re: K2 in GRR Form

The Square root of 2 is 1.41 (1.414213562²=2)
Therefore, with 3 appraisers d2 is 1.732, with 4 appraisers d2 is 2, and so on.

Ryan

d2* Table

The constant d2* (Dee-Two-Star) is read from the Table called "Values for the distribution of the Average Range" given in the MSA Manual.

The values of d2* for reproducibility are:

For 2 appraisers : d2* = 1.41; K2 = 5.15/1.41 = 3.65
For 3 appraisers : d2* = 1.91; K2 = 5.15/1.91 = 2.70

Similarly, d2* used in repeatability calculations depends on No of trials and (No of parts time no of appraisers). So for
3 appraisers, and 10 parts we have the following d2* values:

for 2 trials : d2* = 1.128; K1 = 5.15/1.16 = 4.56
for 3 trials : d2* = 1.693; K1 = 5.15/1.72 = 3.04

For R&R calculations,

For 5 parts, d2* = 2.48; K3 = 5.15/2.48 = 2.08
For 10 parts, d2* = 3.18; K3 = 5.15/3.18 = 1.62

For statistical explanation of these values you will have to refer
"Quality Control And Industrial Statistics" by AJ Duncan.
-Atul.

Thanks for the explanation Atul, you can find more information about in on MSA (measurement Systems Analysis) Febr. 1995 Ford Motor Comp., GM Corp and D.C, , the manual may obtained from AIAG at 810-358-3570, the values in this manual are on page 29


Regards
Arte:thedeal:

Arte,

Yes, the MSA manual has the table. MSA manual also mentions Duncan's book as reference.
I use the values on faith that someone out there would have a valid statistical explanation for them - much like we 'look up' the constants A2, D3, D4... in SPC.

-Atul.