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SMT - Cpk for Attribute Data

C Dooley

#2202

SMT - Cpk for Attribute Data | 13 December, 2000

Is it possible to find the Cpk value for attribute data? We are running into problems due to unspecified LSL/USL values. How can we find the Cpk values without specific LSL/USL? We would also like to get some reference books on this subject so any suggestions are welcome.

Thanks, Dooley

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#2203

Re: SMT - Cpk for Attribute Data | 13 December, 2000

I�ll bite ... Why can�t you calculate LSL/USL values from your control charts? We find that LSL/USL values generally are unknown.

If you are seeking a text on statistical analysis consider: "Statistical Process Control for Surface Mount Technology" (0967503396) William S. Messina, Ph.D., President, Data Sleuths, 8311 Via de Ventura #2075 Scottsdale, AZ 85258: 602-321-0549 Fax: 480-348-9636 datasleuth@yahoo.com "Statistical Methods For Testing, Development, and Manufacturing" [0471540358] FW Breyfogle, Wiley 1992 "Statistical Quality Control" [0070241627] EL Grant, RS Leavenworth, McGraw-Hill 1996

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susan

#2204

Re: SMT - Cpk for Attribute Data | 20 December, 2000

For attribute data, the process capability is reflected by the process average nonconforming (e.g.p bar). Reference the automotive group's AIAG SPC Manual.

Hope this helps, Susan

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