Long and Short (Variable Data) Gage Studies - Urgent Help needed

Hi Experts!!!
I have a question long and short (variable data) gage studies
Its my understanding that long term Gage study is when three operators measure 10 parts three times and Short term gage study is Two operators measure 5 parts two times according to AIAG manual (I don't have this manual now to refer). But our customer is saying Short term study is where operators measure twenty-five samples five times and long term is operators measure eight to ten samples twenty-five times to develop the control chart. I don't understand what our customer is mentioning here? Now my question is, Is my understanding of short and long term gage study correct? Also Can i know when to use long and short term gage study? My understanding is people use short term study when there is a scares of resources.
Last question, is there any special instance that i should be using Xbar R method over ANOVA method? i always use ANOVA method

Appreciate the immediate help.. Thanks in advance for the help.

Your Customer is way off base here.

The AIAG variable gauge study for repeatability and reproducibility is 2 or 3 Operators and 2 or 3 trials on 10 parts. The most extreme would be 3 Operators and 3 trials but that would be a Customer Specific such as Ford.

A short term study was developed years a years ago by GM but it is not used any more.

Better get a book or something so you know what to do with your study.

Good Luck!

Thanks for the information. Can you suggest any good books. All i can find is AIAG manual. Any other good books on this subject?
I was re reading the customer email, another thing customer mentioned is keeping a control chart for the critical gages. Same operator measure same parts every day and plot these points on a control chart to monitor the gage. Anybody out here using this?
Thanks once again for the help

David DeLong said:

Your Customer is way off base here.

The AIAG variable gauge study for repeatability and reproducibility is 2 or 3 Operators and 2 or 3 trials on 10 parts. The most extreme would be 3 Operators and 3 trials but that would be a Customer Specific such as Ford.

A short term study was developed years a years ago by GM but it is not used any more.

Better get a book or something so you know what to do with your study.

Good Luck!

Click to expand...

That method is not a R & R but a stability report. Not many do this although it is in the TS 16949 and also the QS 9000 standard.

I do have a seminar book on R & R studies but I am not here to sell books but help in advice.

The AIAG book is pretty good on variable studies but this time around they want a % of the process rather than the spec. Make sure that the customer know that you will be using % of spec.

Hope this helps

Thanks for the information. I don't have the TS 16949 standard book. I might buy this book some time this week unless somebody recommend a better book.
thanks once again

David DeLong said:

That method is not a R & R but a stability report. Not many do this although it is in the TS 16949 and also the QS 9000 standard.

I do have a seminar book on R & R studies but I am not here to sell books but help in advice.

The AIAG book is pretty good on variable studies but this time around they want a % of the process rather than the spec. Make sure that the customer know that you will be using % of spec.

Hope this helps

Click to expand...

peach said:

Hi Experts!!!
Last question, is there any special instance that i should be using Xbar R method over ANOVA method? i always use ANOVA method.

Click to expand...

See the following thread for an explanation of Range method over ANOVA. The only advantage of the Range method is when performing calculations manually. If your software supports ANOVA, I would use it always.