List of SPC calculations

[Former Member]

Can anyone give me a list (formulas) of how MII auto-calculates center lines and control limits for the charts offered in iSPC?

Our six sigma person is asking how these values are calculated, if auto-calculation is enabled. Different styles of calculating control limits for a single chart exist in the SPC literature.

For example, I would assume Xbar charts are broken down like so:

UCL: x bar center line + A2 * R chart center line

CL: grand average of sampled subgroups

LCL: x bar chart center line - A2 * R chart center line

But you know what they say about assuming. I looked for these formulas in MII help but couldn't find anything.

Thanks

[Former Member · Accepted solution]

Justin,

I was able to extract these calculations from the 11.5 help , I do not remember how I did it , but I still have a copy.

If you could update your Business Card with an e mail ID I could send it to you.

[Former Member · Accepted solution]

Hi thanks for your help. I have updated my business card with e mail ID, if you could send that document along.

Thanks,

Justin