I have a question about using MMC on the SPC feature and how will it affect the UCL on capability charts. I'm doing capability studies on the 0.25 MMC position but this could change with the size of the feature so what will UCL be for the chart?
If you HAVE to use the bonus because you can't hold the feature in the declared value (0.25) and depending on how people around this issue feel about it...
You could subtract the bonus from your actual so that the UT stays static giving you a UCL that is solvable as a single value.
On reports, report the actual with the bonus, but, with a statement as to what you are doing and why, remove the bonus from the actual.
That is if you HAVE to use the bonus.
If you don't HAVE to use the bonus, just don't use it.
You will show less control, but if you run it without any bonus and run it like I said, write a position to engineering showing the delta, I would think no one would have an issue with a higher control value given the lack of full tolerance usage.
This isn't a direct answer to your question, but it is what I would do if I was needing to submit to a customer or justify some sampling rate.
If you HAVE to use the bonus because you can't hold the feature in the declared value (0.25) and depending on how people around this issue feel about it...
You could subtract the bonus from your actual so that the UT stays static giving you a UCL that is solvable as a single value.
On reports, report the actual with the bonus, but, with a statement as to what you are doing and why, remove the bonus from the actual.
That is if you HAVE to use the bonus.
If you don't HAVE to use the bonus, just don't use it.
You will show less control, but if you run it without any bonus and run it like I said, write a position to engineering showing the delta, I would think no one would have an issue with a higher control value given the lack of full tolerance usage.
This isn't a direct answer to your question, but it is what I would do if I was needing to submit to a customer or justify some sampling rate.
