过程性能指数（Ppk）

The Process Performance Index (Ppk) is a statistical measure that evaluates the capability of a manufacturing process to produce output within specified limits, reflecting both the process variability and its mean relative to the target specifications. It is calculated by assessing the difference between the process mean and the nearest specification limit, normalized by the process standard deviation, thereby providing insights into the process’s ability to meet quality standards. A higher Ppk value indicates a more capable process, essential for ensuring product consistency and reliability in design, innovation, and production.