Repeatability Type 1 Gage and Gage R&R

[Ranma]

Hello everyone,
first of all very great forum, I hope I will find clarification here.

So during my six sigma class i learnt about Gage R&R of course. We covered only the Gage R&R Study and now, for a project, i'm learing about Type 1 Gage study too.

There is one thing that i cannot understand:

what is the difference between the repeatability of the Type 1 Gage and the repeatability of Gage R&R?

Since this study will assume some stops of the production machine i'm trying to understand if there is additional value in performing also the type 1 or i can just perform the Gage R&R.
I understood type 1 focus only on the repeatability and bias of the gage so without any other source of variation but what i'm thinking is that with the gage R&R i can cover anything.
I have the feeling i'm wrong so here i'm am asking advice between these two studies.

Sorry for the naive question but english is not my first language and i cannot find literature about this is my native language so maybe is a very simple topic that i just cannot understand.

Thank you very much

 

[Miner]

You can get the same information from the R&R study. The Type 1 study is typically performed when there is no possibility for Reproducibility (appraiser) variation, such as with automated test equipment, or a special situation such as a lab test where there is only one appraiser.

Some (but not all) instructions for the Type 1 study specify that you use standards instead of parts. This would also remove the potential for within part variation to affect the results.

 

[Ranma]

You can get the same information from the R&R study. The Type 1 study is typically performed when there is no possibility for Reproducibility (appraiser) variation, such as with automated test equipment, or a special situation such as a lab test where there is only one appraiser.

Some (but not all) instructions for the Type 1 study specify that you use standards instead of parts. This would also remove the potential for within part variation to affect the results.

Thank you for the quick answer. It is more cleare for me now.

When you say "use standards instead of parts" you mean using standard known product instead of random sample?

My scenario is the follow:

We have automated camera to check the dimensions of the product.

There is this machine that has 2 camera that check the measeures so i was thinking to study the reproducibility between these two cameras since they performe the same measures therefore i was thinking of use Gage R&R.
Then there is a third camera that check another kind of measures, but it is only one camera per machine so for the reproducibility i was thinking to performe the gage using two cameras (same kind of camera of course so same hardware/software and same condition) as appraisers from different machine.

In this scenario, based on what i understood, i can just performe Gage R&R without the type 1 in advance, is that correct?

Thank you!

 

[Miner]

When you say "use standards instead of parts" you mean using standard known product instead of random sample?

That is one option. Another is to use calibration standards. The intent is to isolate the repeatability due solely to the measurement device.

My scenario is the follow:

We have automated camera to check the dimensions of the product.

There is this machine that has 2 camera that check the measures so i was thinking to study the reproducibility between these two cameras since they perform the same measures therefore i was thinking of use Gage R&R.

I would recommend this approach as well. Two different cameras are the same as two different operators and will probably measure differently from each other.

Then there is a third camera that check another kind of measures, but it is only one camera per machine so for the reproducibility i was thinking to perform the gage using two cameras (same kind of camera of course so same hardware/software and same condition) as appraisers from different machine.

In this scenario, based on what i understood, i can just perform Gage R&R without the type 1 in advance, is that correct?

Unless you plan to add a second camera permanently, I do not recommend this plan, but would use the Type 1 Repeatability study.

 

[Ranma]

Thank you again.

Unless you plan to add a second camera permanently, I do not recommend this plan, but would use the Type 1 Repeatability study.

My explanation to this would be that using a second camera on another machine add too many source of variation and we cannot say that the gage is perfomed on the same condition in both machine