What is Model drift?
A system that was accurate at handover quietly becoming less so as the world it was measured against changes.
Drift is not a defect. It is what happens when a supplier changes its invoice template, a regulation is amended, a new site comes online with different conventions, or a reorganisation renames a cost centre. The model is unchanged; what it was measured against is not.
Which is why monitoring against the baseline established before the build matters more than the accuracy figure at handover, and why oversight is a separate purchase rather than a warranty. Without a baseline there is nothing to drift from, and the first anyone hears about it is a complaint.
| On this | Model drift | A support contract |
|---|---|---|
| What it watches | Whether the system is still as accurate as it was | Whether the system is running |
| What triggers it | A measured decline against the baseline | Somebody reporting a problem |
| What it produces | A recommendation, and a judgment on whether it needs its own engagement | A fix for the symptom reported |
- When it is the right answer
- From the day a system reaches production. The cheapest version is instrumenting it during the build, which is why monitoring is part of implementation rather than an add-on.
Start here
If a term here is the one your board paper turns on, ask us about it.
We will send the entry, the evidence behind it, and the honest note about where it does not apply.
You get a reply within one working day, from the engineer who would do the work - not a sales sequence.