Process-Stability

I set up a job drilling 50mm bores through 2-meter hydraulic cylinder barrels. The material was consistent, the machine was aligned, and the coolant system was working perfectly. I knew within the first three parts that this job was going to be a good one. The machine sounded different. The chips looked right. The gauges were all in the green. I have learned to trust that feeling. When everything lines up, the machine tells you before the micrometer does. ...

Why Intermittent Problems Are Different I have spent more hours than I care to count standing at a machine, waiting for an intermittent problem to reappear. The part that makes these issues so frustrating is obvious: if the fault fired every cycle, I could isolate it in an afternoon. But when a tool burns up on one part, runs fine for the next ten, and then burns up again on part twelve, you are no longer troubleshooting a single event. You are chasing a condition that crosses some invisible threshold only part of the time. ...