Gage R&R studies used in uncertainty calculations

[t_partlow]

I am a little confused on a few things. I am relatively new to R&R's and uncertainty, but thought I could figure it out on my own. I was wrong! First, I know that the more data the better the resluts will be. However, can I use the results of a R&R with 3 appraisers, 3 trials, and 10 parts to represent all personnel (6 total) within a given laboratory? Second, when calculating the measurement uncertainty for a given gage, the budget includes a line item for repeatability, is this purely the gage variability from the R&R or the combination of the appraiser and gage variability? Lastly, where is a good place to find a spreadsheet for calculating gage R&R's? Thanks for the help!

[Marc]

Here's one more for one of the Experts here. Anyone?

Of course, there are plenty of excel spreadsheets here that calculate R&R in various configurations - check the attachments listing.

[Hershal]

This appears to be a QS related question, so for most of it I will let someone else answer, but I will throw in a penny or two.

The easy way (not textbook, but it works) to describe repeatability and reproducibility is that repeatability means you can sit with a gage (e.g. calipers), take some number of readings, and they will be the same, plus/minus measurement uncertainty. Reproducibility means you can give the calipers to someone else tomorrow and get the same results, plus/minus the measurement uncertainty.

The Gage R&R really address what is known as Type A (the instrument) pretty well. It tends to roll Type B (other influences like operator and environmental) in so they become masked in the sense of accounting for the uncertainty influences. That is not a bad thing, but sometimes makes the task of accounting for the various influences a bit less clear.

I may have made it a bit less clear already, but hopefully other will clear this up better - and likely correct me in the process.

Hershal