Manage a team through eight quarters of noisy results. You'll be quietly trained to chase noise — then shown, at the end, how little of it was ever yours to manage.
Your learning receipt
A quarter of anyone's output is one noisy sample from a person-in-system process whose baseline the system sets — scope, dependencies, luck, drag. Deming's claim was that the system dwarfs the individual as a source of variance. React to each swing as a special cause — a real, assignable signal — when it's just this month's draw, and you're tampering: adding variance, not removing it.
And regression to the mean makes the tampering feel vindicated. Praise your best quarter and it falls back — "praise breeds complacency". Warn your worst and it bounces — "tough love works". Both are pure regression; you learn to manage exactly wrong. This is the flight-instructor illusion, and here it happens to you.
The routine-variation band is an oracle — you only get it in a simulation; your real team doesn't come with one. What transfers isn't the band, it's the question every swing deserves: spike, or shift? A single point outside the band can be luck; only a sustained walk out of it is a signal worth a conversation.