S
Sara013
Hi...! First off, let me warn you that I'm an R&D Engineer and (clearly) not at all an expert in Gage R&R studies. I really don't know all of the proper terminology, so I apologize ahead of time. I used to have a wonderful Quality Engineer guiding me through all of this, but that was years ago and at a different company.... So, if you can help, feel free to use small words so I can understand.
Here's my current situation:
Any advice? Guidance? Thoughts? Am I looking at the wrong thing, am I misinterpreting the data, etc.?
Any help you could give me would be greatly appreciated.
Here's my current situation:
5 Test Units
3 Operators
2 tests per unit
Ought to be a straight forward Gage R&R. But....
Each operator, as a stand-alone, demonstrates a very high degree of repeatibility, based on a one-way ANOVA.
With all three operators together, the total Gage R&R %SV accounts for upwards of 60-80% depending on which test I'm analyzing. And that tells me the test method is not reproducible. (Right?)
So I tried a quick experiment with the original operator (who has the greatest amount of experience) performing the testing again, several days after their first round of testing.
Again, compared to that operator's original data, each group of data individually demonstrated high repeatability; together, the data showed horribly poor reproducibility.
I'm currently going through all the processes, trying to find and clarify any possible point of variation, but here's my fear:
It is very possible that the product itself is the source of variation. None of the test units are from the same manufacturing lot, there's no telling how often the test units were used before, there's no telling how or when the tests units were made, and there's no telling how the test units might degrade over time and use.
Not my ideal batch for Gage R&R, but it's what my customer has requested.
My first instinct was to find a representative test unit with everything known and consistent, and just test that (or several of that) to focus on the method and the operator without the added trouble of inconsistent, unknown parts.
So... if you've read this far, thank you, I really do appreciate it.3 Operators
2 tests per unit
Ought to be a straight forward Gage R&R. But....
Each operator, as a stand-alone, demonstrates a very high degree of repeatibility, based on a one-way ANOVA.
With all three operators together, the total Gage R&R %SV accounts for upwards of 60-80% depending on which test I'm analyzing. And that tells me the test method is not reproducible. (Right?)
So I tried a quick experiment with the original operator (who has the greatest amount of experience) performing the testing again, several days after their first round of testing.
Again, compared to that operator's original data, each group of data individually demonstrated high repeatability; together, the data showed horribly poor reproducibility.
I'm currently going through all the processes, trying to find and clarify any possible point of variation, but here's my fear:
It is very possible that the product itself is the source of variation. None of the test units are from the same manufacturing lot, there's no telling how often the test units were used before, there's no telling how or when the tests units were made, and there's no telling how the test units might degrade over time and use.
Not my ideal batch for Gage R&R, but it's what my customer has requested.
My first instinct was to find a representative test unit with everything known and consistent, and just test that (or several of that) to focus on the method and the operator without the added trouble of inconsistent, unknown parts.
Any advice? Guidance? Thoughts? Am I looking at the wrong thing, am I misinterpreting the data, etc.?
Any help you could give me would be greatly appreciated.