Chronostatistics: A powerful, pragmatic way to assess the validity of existing process control data

摘要

Forty years ago Dr. Pierre M. Gy, a metallurgist, introduced variography as applied to monitoring a process. Consequently, his followers used the variogram to elaborate meaningful process control charts, especially since 1993 and 2006. When investigating a dynamic process using Chronostatistics, there is no such thing as a stationary variogram. Still, the evolving variogram provides essential information about subtle, often overlooked process difficulties.