Estimate Versioning

Estimate versioning is the practice of keeping every prior estimate beside its successor, with its own cutoff date and method version, so that accuracy and drift can be audited after the fact.

An estimate that is overwritten cannot be checked. Versioning stores each band as it was issued, the evidence that triggered the update and the method version used, and displays the history as part of the record.

The practice makes learning possible. Comparing the estimate at underwriting with the estimate at each checkpoint shows which months of delay were structural and which were recoverable, and shows whether a method's early estimates were honest about their uncertainty.

Versioning is not the same as retraining. A model can be retrained without any change to the estimates already issued, and the preserved history is how that independence is shown.