What does the letters cpk stand for in 6 sigma?

In Six Sigma, the letters "CpK" stand for "Process Capability Index." It is a statistical measure that evaluates how well a process can produce output within specified limits. CpK specifically considers both the process variation and how centered the process is relative to the target specification, providing insight into the capability of the process to meet quality standards. A higher CpK value indicates a more capable process.