Talk:Process capability index/Archives/2011

... and how are these interpreted?
It would be really helpful, I think, if someone could add a sentence or two for each measure to say what a "good" value is ... e.g., 1.0 is good, higher is better, things like that. Sn14534 13:13, 19 July 2007 (UTC)

Cpk
I have noticed that the Ckp value equation has an mistake; there shoud be T instead of µ (targed instead of estimated/calculated mean). If µ is used, the result is PPk. Could someone make the correction, please.

Antti 29th Aug 2007 —Preceding unsigned comment added by 192.130.237.254 (talk) 06:57, August 29, 2007 (UTC)


 * Cpk does not take the target, T, into account according to NIST (http://www.itl.nist.gov/div898/handbook/pmc/section1/pmc16.htm) or Montgomery (http://he-cda.wiley.com/WileyCDA/HigherEdTitle/productCd-0471656313.html). Perhaps you're thinking of a variant on Cpk that does?  — DanielPenfield 16:24, 5 September 2007 (UTC)

Is there a missing word in the following clause? 'is', maybe? And is this English? I'd much prefer "Because the process capability..."

Being the process capability a function of the specification --71.10.226.43 (talk) 12:28, 18 September 2009 (UTC)

Please see 8-14b on the following link: http://www.math.wsu.edu/math/faculty/lih/10-11s.pdf; regarding your statement about Cpk, you say that, "Estimates what the process is capable of producing if the process target is centered between the specification limits." The word, NOT, should be added before the word centered and the word "target" needs to be replaced with the words estimator of process mean uhat or simply xbar. Cpk is calculated when the process mean is not centered. Do you agree? Jun 30 2011
 * I've attempted to clarify. -- DanielPenfield (talk) 20:57, 30 June 2011 (UTC)
 * I've actually corrected the statement 18 AUG 2011 — Preceding unsigned comment added by 75.215.56.118 (talk) 20:03, 18 August 2011 (UTC)
 * Not really--you just reworded it. -- DanielPenfield (talk) 21:33, 18 August 2011 (UTC)