# AI Model Drift Monitoring Templates and Response Protocol

A monitoring setup that catches a model degrading before users do. A metrics specification by model type, an alert threshold worksheet, an ownership register, and a drift response protocol with yellow and red actions.

**Who this is for:** The ML or platform owner responsible for a model once it is in production.

Source playbook: https://aigovernance.com/playbook/model-drift-monitoring

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## Monitoring metrics specification

_What to measure, by model type. Input drift, output drift, performance, and (where people are affected) fairness._

### Template

| Metric | Model types | What it detects | Source | Cadence |
|---|---|---|---|---|
| Input feature drift (PSI / KL) | all | inputs shifting away from training distribution | inference logs vs. training baseline | daily |
| Prediction distribution shift | all | output mix changing | inference logs | daily |
| Performance vs. ground truth | where labels arrive | accuracy / error decay | labels joined to predictions | weekly or on label arrival |
| Calibration | scoring models | predicted vs. actual rates diverging | outcomes | weekly |
| Fairness metrics | people-affecting | disparity emerging | scored outcomes by group | monthly |
| Latency / error rate | all | serving degradation | serving metrics | real-time |

### Worked example

| Metric | For fraud-scoring | Baseline | Cadence |
|---|---|---|---|
| Input drift (PSI) | on 12 key features | training distribution snapshot | daily |
| Score distribution | share above the hold threshold | 4.2% at launch | daily |
| Precision / recall | vs. confirmed-fraud labels (arrive ~10 days later) | P 0.88 / R 0.71 | weekly |
| Calibration | predicted vs. actual fraud rate by score band | curve at launch | weekly |
| Adverse-impact ratio | by protected group on holds | 0.94 at launch | monthly |

### Acceptance criteria

- Every production model has a metrics spec appropriate to its type.
- A training-time baseline is stored for every drift metric.
- People-affecting models include a fairness metric on the same cadence as review.

---

## Alert threshold setting worksheet

_Turns each metric into a yellow (watch) and red (act) threshold, justified rather than guessed._

### Template

| Metric | Baseline | Normal variation (from history) | Yellow threshold | Red threshold | Rationale |
|---|---|---|---|---|---|
| <metric> | | | | | |

### Worked example

| Metric | Baseline | Normal variation | Yellow | Red | Rationale |
|---|---|---|---|---|---|
| Input drift PSI (max feature) | 0 | up to 0.10 in a stable month | 0.15 | 0.25 | PSI > 0.25 historically preceded a precision drop |
| Score share above hold threshold | 4.2% | 3.8-4.8% | outside 3.5-5.5% for 2 days | outside 3-6% for 1 day | fraud rate does move; sustained shift is the signal |
| Precision | 0.88 | 0.85-0.90 weekly | < 0.85 | < 0.80 | 0.80 is the business floor for analyst load |
| Adverse-impact ratio | 0.94 | 0.90-0.97 | < 0.88 | < 0.80 | 0.80 is the four-fifths line |

### Acceptance criteria

- Thresholds are set from historical variation and a business floor, not round numbers alone.
- Every metric has both a yellow and a red threshold.
- Each threshold has a one-line rationale.

---

## Monitoring ownership register

_Each system to its monitoring owner and the review cadence, so alerts have a destination._

### Template

| System | Monitoring owner | On-call route | Dashboard review cadence | Escalation contact |
|---|---|---|---|---|
| <system> | <name> | <alert channel> | weekly / monthly | <role> |

### Worked example

| System | Monitoring owner | On-call route | Review cadence | Escalation |
|---|---|---|---|---|
| fraud-scoring | ML Platform (D. Reyes) | pager: ml-oncall | weekly dashboard review | Head of Risk Ops |
| resume-screener | DS team (R. Nkemelu) | slack: #ds-alerts | monthly + on any yellow | Head of Talent |

### Acceptance criteria

- Every production model has a named monitoring owner and an alert route.
- Dashboard reviews happen on a set cadence, not only when alerts fire.
- An escalation contact is named for red events.

---

## Drift response protocol

_What happens at yellow and at red: who is told, what is checked, and the response options._

### Template

| Level | Trigger | Notify within | Diagnostic steps | Response options |
|---|---|---|---|---|
| Yellow | any metric past its yellow threshold | 1 business day | check for data pipeline change, seasonality, upstream vendor change; widen sampling | monitor closely; schedule retrain; adjust threshold if a legitimate shift |
| Red | any metric past red, or yellow sustained N days | same day, to escalation contact | full diagnosis; compare to last known good; check for incident | roll back to last good version; disable and fall back to manual/rules; expedited retrain; pause if people are harmed |

### Worked example

> Red event, 2026-09-05, fraud-scoring.

| Step | What happened |
|---|---|
| Trigger | precision fell to 0.78 over two weekly readings; input drift PSI 0.27 on "merchant category" |
| Notify | Head of Risk Ops, same day |
| Diagnosis | a payments partner changed merchant-category coding; the feature meaning shifted |
| Response | rolled back to the rules-engine fallback for affected categories; expedited retrain on remapped categories |
| Outcome | back on the model 4 days later at P 0.87; logged as a Sev-2 incident; post-incident review scheduled |

### Acceptance criteria

- Yellow and red each have a notification target and a time.
- Diagnostic steps come before response, so you do not retrain on a pipeline bug.
- Red responses include a fallback that does not depend on the degraded model.

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## Governance controls this kit produces evidence for

- **MON-002**: The metrics spec and thresholds are the model drift detection mechanism.
- **MON-001**: The stored training-time baselines are the AI performance baseline.
- **MON-005**: The review cadence and response protocol are continuous model evaluation.
- **MON-004**: Prediction-distribution and calibration monitoring are output anomaly detection.
- **CHM-003**: The red-level rollback and fallback options are the model rollback and emergency shutdown path.
