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.
“You’re chasing your tail,” she said. “The crusher power draw spikes, you back off. It drops, you tighten. But the lag in your feedback means you’re always reacting to what happened five minutes ago. By the time you fix it, the feed has already changed. You’re creating the instability you’re trying to solve.” Statistical Methods For Mineral Engineers
“Here to fix what ain’t broke, Doc?” he grunted. She drew a Shewhart control chart on a
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. And in the center, the target P80 of 150 microns