All physical processes have some amount of natural randomness. A manufacturing process is a *random process* if all assignable causes are eliminated. A process is "in statistical control" if the only observed variation is from the underlying inherent randomness. Corrolary =>If a process is anything but pure random, then we can still improve it. I.e. have I eliminated (controlled for) everything external to the process that could cause it to vary (purely random, stationary behavior). [[Shewhart]], [[Bell Labs]] circa 1925. --- - Links: [[MIT 2.830J Control of Manufacturing Processes - Lec 7]] - Created at: [[2021-11-28]]