
Re: CPK Formula
daingerous Aug 9, 2012 4:03 PM (in response to Brian Summ)I too would like help on this.

Re: CPK Formula
Boris Gerchikov Aug 9, 2012 5:00 PM (in response to daingerous)I've never done it before, but I'd suggest to use Statistics Chart Wizard in Tools menu using QV Help guidelines. It allows to operate many of known statistical functions.
Hope it will help.


Re: CPK Formula
daingerous Aug 10, 2012 1:04 PM (in response to Brian Summ)Good info here, Im trying to work on the formula now.

Re: CPK Formula
Brian Summ Aug 10, 2012 1:24 PM (in response to daingerous)Yup, SPC is sometimes challenging. Attached is a formula that works.

CPK.txt 874 bytes

Re: CPK Formula
daingerous Aug 10, 2012 1:59 PM (in response to Brian Summ)What verison of Qilkview are you using? Also, if both my min and max are defined do I need the bottom half the formula?

Re: CPK Formula
Brian Summ Aug 10, 2012 2:55 PM (in response to daingerous)Using ver 11. But the formula I sent you was written in ver 7. Don’t really need the second half but our consultant at the time (ver 7) want to be sure to account for missing values. If I really wanted to be very accurate I would use this formula: cpk =cp*((1((ABS(targetmean))/MIN(targetLSL,USLtarget)))) This formula is intended to compensate for asymetric specs; eg: LSL 5 Target 10 USL 17.
Hope this helps.


