Help with measurement system analysis with destructive samples

#1
Hello everyone,

I am an internship student and for my company I have to develop a method to test if their material is brittle or not. They bought a new machine so first I have to start with an MSA (measurement system analysis).

I would like to test the repeatability and reproducibility (Gage R&R). The problems are : I can only use 1 operator (myself), the samples are destructive (they burst during testing so the same sample can't be tested a 2nd time), I have no reference values since this is the first time this machine is used with this kind of material. I try to avoid the part to part variation by using thick paper as reference, this paper is almost uniform in thickness and in bursting strength. So for now I have the following data:

50 samples of thick paper tested once, all tested by the same operator, 50 single results...

I tried to use the nested Gage R&R in minitab but I keep getting errors because it requires 2 operators and it requires replicate results (although the troubleshooting says it's not necessary and that this method is perfect for destructive testing with 1 operator)

Can someone please help me?
Thank you very much in advance !
 

Miner

TS Contributor
#3
I have a blog on a quality forum. Here is a blog post on R&R for Non-replicable Measurements.

There are a couple issues with your approach. First, Reproducibility requires multiple operators, so you can only assess Repeatability. Second, the nested R&R assumes parts are nested within operators, and yours are not. You can use Minitab to analyze a Type 1 Gage Study, which assesses the bias and repeatability. It does ask for a reference value, which you stated you do not have. Just enter the average of the 50 measurements and ignore the Bias results. The repeatability results will be correct.