Which calculation method does JMP use for MSA?

Florian_Vogt

Hi all,

 

a prospect asked me which calculation method JMP uses in the MSA platform (R&R calculation).

 

There appears to be a reference (MSA 4th Edition) and, as the customer stated, different standards in the US and  other parts of the planet. MSA 4th Edition uses ANOVA, before that the Average Range Method was standard.

 

This is what I found so far, but I couldn't find which method JMP is using.

It appeared to be something obvious - could somebody please enlighten me? 

Jason_Wiggins

Hey Florian

Are they referring to the variance components estimates used in the %R&R calculation?

If so, I believe Restricted Maximum Likelihood method is used to estimate the variance components. To convince yourself of this, In Fit model, specify Operator, Part and Operator*Part as random effects. Use the default  personality and method (REML). Select Estimate Only Variance Components. The output is a table of variance components estimates.

Now do the same thing in the MSA platform choosing Gauge R&R method. Choose Variance components from the red triangle menu. The tables should match.

The file I uploaded has two scripts you can check out. One for Gauge R&R and the other for REML estimates if you want a quick look.

I am unaware of any circumstances that would differ. If there are, I would love to know them as well.

Best,

J

StandardMSA.jmp