Examples

Noise vs Actionable Change in Plating Processes | Lab Wizard

Noise vs Actionable Change in Plating Processes

A nickel plating run finishes and the thickness readings show a slight shift from the previous batch. The operator adjusts the rectifier current. The next batch shifts back the other way. Another adjustment. Three runs later, the process is more variable than it was before anyone touched anything.

Why Process Changes Become Quality Problems | Lab Wizard

Why Process Changes Become Quality Problems

A barrel plating shift supervisor notices the rectifier current dropped 8% during the first hour of a run. He adjusts the amperage, adds a chemistry check to the log, and calls it a minor fluctuation. Three hours later, another operator sees the same tank’s conductivity creeping upward by 2 mS/cm per hour. This time, he stops the line, pulls a test panel, and calls for a chemistry adjustment. The part brightness is still within spec, but the trend is directional and sustained. By the time the shift ends, a batch of connectors has plating thickness variation that passes lab tests but fails the customer’s visual inspection.

Not All Process Changes Mean the Same Thing | Lab Wizard

The Operator’s Dilemma

A shift supervisor notices the cathode current density has shifted from 18.0 to 19.5 A/sq dm. The documented range is 16-22. The change is within spec.