Risk & governance
Model or system drift
Performance changing as models, data, users or environments evolve.
Definition
Drift is a change in input patterns, system components or outcomes that makes previous evaluation results less representative.
Why it matters
A system that passed before deployment can degrade after model updates, policy changes or shifts in user behaviour.
Related concepts
- System under test
The complete configuration being evaluated—not only the model.
- Continuous evaluation
Rerunning tests as a system and its environment change.
- Production monitoring
Observing system behaviour and outcomes after deployment.