Hello,
According to IATF 16949 I wanted to validate my worksheet for Cp/Cpk, Pp/Ppk calculations. I have used data set from page 186 of AIAG SPC edition 2 manual. Everything seems to be fine except of total sigma. My calculation is 0,188657 but in the manual there is 0,189037. I copied the data by hand from the manual, so I searched for a bug for a long time, but didn't find it. Additionally, total mean and sigma for within variation (Rbar/d2) is correct in my calculations based on copied data.
Does this mean there is a mistake in the manual? I realize that this is not a very significant difference, but an auditor who wants to compare my calculations with the manual may question their correctness. Can you confirm my calculations ?
According to IATF 16949 I wanted to validate my worksheet for Cp/Cpk, Pp/Ppk calculations. I have used data set from page 186 of AIAG SPC edition 2 manual. Everything seems to be fine except of total sigma. My calculation is 0,188657 but in the manual there is 0,189037. I copied the data by hand from the manual, so I searched for a bug for a long time, but didn't find it. Additionally, total mean and sigma for within variation (Rbar/d2) is correct in my calculations based on copied data.
Does this mean there is a mistake in the manual? I realize that this is not a very significant difference, but an auditor who wants to compare my calculations with the manual may question their correctness. Can you confirm my calculations ?