Guardrail metric

The target is the number you are trying to move. The guardrail is what that move might cost.

Reduce handle time and repeat contacts can rise, because faster replies are less complete. Close more tickets and reopens can rise. Speed up a process and the hard cases pile onto whoever is left handling them. In each case the shortcut that satisfies the target shows up in the guardrail, which is the point.

A guardrail needs a tolerance rather than a direction. "Satisfaction shouldn't drop" is not usable — every metric moves. "Satisfaction holds within two points of the four weeks before the change" is, and the two points should be wider than the metric's normal week-to-week swing or it will trip on noise.

Three is a workable number. Name eight and something is always outside tolerance, every result becomes arguable, and people stop looking.

Naming them afterwards does not count. A guardrail identified once the results are in is a post-hoc analysis, and everyone reading it can tell.