Nov 12, 2021
Introduction to Statistical Process Control
https://knowledge-swami.com/introduction-to-statistical-process-control/
The CP and CPK are statistics used to check the capability of the process.
Cp in SPC
CP can be defined as the ratio between specification limit and process width. Here, specification limit refers to the customer requirement. Process width is derived from the upper control limit (UCL) and lower control limit (LCL).
Cpk in SPC
CPK indicates a process spread shift from the mean. k indicates centralizing factor. CPk is calculated as per the formula stated in the above graphics.