Manufacturing capabilities (SPC introduction) ─CPK of the process capabilities explained

CPK's process capability explained

CPK is the CI of the accuracy and the standard of the process capability.

Cpk= (1-ck)? C P
That is, at the same time as the CP, consider taking a (1-ck) number, to Praya the deficiency of the CP, the maximum time is 1, that is (ck=0) (the center value is not biased), if the central value is not too large, the number of this relationship (1-CK) will be smaller, the CPK would also become smaller.

C PK rating of the class

						 
a			CPK	≧	< Span style= "font-family:arial;" >2.00	&NBSP;	> The process capability is very good, and you don't have to check it to reach the PPM water standard.
b	2.00	>	CPK	≧	1.33	&NBSP;	The capacity of the process is sufficient, do not need to check, to maintain the status can be.   cpk=1.66 at 0.6358ppm
c	1.33	>	CPK	≧	1.00	&NBSP;	The capacity of the ordinary, can hold 2 months now, need to look for improvement, in this period, to check.   the Cpk=1 has a 2700ppm defect rate, and the cpk=1.33 is 66.08ppm.
D	1.00	>	Cpk				The process capability is insufficient and needs to be rapidly sought for improvement, which requires a full number of checks.

Manufacturing capabilities (SPC introduction) ─CPK of the process capabilities explained