Richard, you can still use the central limit theorem for averages from the data population and do your analysis on the means instead of the individual values. I would be curious to know if/how that works out Regards, Amol Kane | Process Engineer AsteelFlash Group - US East 941 Route 38, Owego NY 13827 Phone: (607) 687-7669 Extn 349 | Website: www.asteelflash.com -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Kraszewski Sent: Friday, February 17, 2012 3:22 PM To: [log in to unmask] Subject: Re: [TN] Correlation Factors for ROSE Testing & Cpk Thanks to all who responded to this string. Realized it could strike a chord. To carry this a step further on a very related topic... Any of you guys ever try to run a Cpk on ROSE data sets? Most of the times I've tried to over the years, the data sets have been non-normal, single tailed distributions, with highest counts near zero and then tailing off towards 10.06. (Similar to having only the right side half of a normal distribution curve). They have defied data transformation to a normal distribution, hence can't really run a proper capability analysis (data of course must be normal for a Cpk). You could of course (at least within Minitab) try to run as a non-normal distribution and just report a PpK, however with such a high count near zero it's next to impossible to find a statistically supportable non-normal distribution. I would appreciate any related experiences and/or thoughts on this topic. Rich Kraszewski -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Kraszewski Sent: Thursday, February 16, 2012 2:00 PM To: [log in to unmask] Subject: [TN] Correlation Factors for ROSE Testing While I realize that IPC specifically and the industry in general, does not support the use of ROSE correlation factors for the various testers, I have a need to see the official document that at one time quoted these specifically allowed factors. I took a cursory look though all 230 pages of IPC TR 583 and didn't see that table. I seem to recall a military specification that had that table. Was it 454? 28809, 2000? Does anyone recall? Rich Kraszewski / PLEXUS ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________