Forecast error and forecast accuracy

A forecast is not a promise; it is an input to a choice. This primer uses forecast error and forecast accuracy to make that distinction concrete.

Practitioner lens

A forecast review of forecast error and forecast accuracy should separate systematic bias from random error. The direction of misses can matter more to inventory decisions than a single accuracy score.

First experiment

Draw the series before fitting a model; mark missing periods, stockouts, promotions and calendar changes.

This is an original educational brief. It is a starting point for discussion, not a claim that one technique fits every supply chain.