The mine manager’s next text was less congratulatory and more confused. “Why did our instantaneous rate drop but our total tonnage increase?”
Dr. Elara Vance stared at the raw tonnage report from the new crushing circuit. The number was good—really good. Throughput was up 12% from last quarter. Her phone buzzed with a congratulatory text from the mine manager. Statistical Methods For Mineral Engineers
She drew a Shewhart control chart on a whiteboard in the control room. Upper control limit. Lower control limit. And in the center, the target P80 of 150 microns. The mine manager’s next text was less congratulatory
“Here to fix what ain’t broke, Doc?” he grunted. Statistical Methods For Mineral Engineers
She didn't celebrate. She opened her laptop instead.