That 3.4 ppm defects with "six sigma" is based on allowance of the process mean shifting by 1.5 sigma. Without the allowance, six sigma would actually be less than 1 ppm. The numbers without that process mean shift allowance are: Cp x-sigma total outside two-sided spec. limits 0.5 1.5 13.36% 0.67 2 4.55% 1 3 0.3% 1.33 4 64 ppm 1.63 4.9 1 ppm 2 6 0 figures from Juran Quality Handbook, 5th Ed. Table 22.4 Timothy Reeves ECD Circuit Board Division 13626 South Freeman Road Mulino, OR 97042 [log in to unmask] (503) 829-9108 (800) 228-8198 FAX (503) 829-5482 > ---------- > From: Hollandsworth, Ron > Sent: Tuesday, February 8, 2000 5:40 AM > Subject: Subj: Six Sigma > > Good Morning TechNetters! > Here is a brain teaser for this early morning. Thinking six sigma. Six > sigma is suppose to be 3.4 PPM. Good! Now what is five sigma, four, > three, > two , one. There is a chart that shows that relationship of a certain > sigma > and the PPM associated with that particular sigma value. > > Ok, the first five to get the right answer will be eligible to go on to > the > "Who wants to be a Black Belt" show. Enough levity, can someone help me > out. Do you know the chart I am referring to? Can you send me the values > and I'll make a chart. > > Grasshopper Ron > ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################