71% fewer false alarms by replacing thresholds with one anomaly model.
A specialty chemicals plant retires hand-tuned alarm bands and lets the model speak.
- 14:22HIGHCMP_042 residual +3.2σ
- 11:08MEDDRY_B drift trend
- 07:41LOWBLR_01 efficiency dip
- 02:15HIGHPUMP_07 cavitation pattern
What was happening before.
True upsets were buried in nuisance alarms. The HSE team flagged alarm fatigue as a top-three risk before the project began.
- Cannot remove safety-instrumented alarms; only nuisance process alarms are in scope.
- Every replaced alarm has a recorded justification with sign-off.
- Operator acknowledges every model alert with a one-click outcome label.
What we built, on what data.
- › Historian tags across the reactor unit and feed train
- › Alarm history: source tag, time, ack, comment
- › Shift logs
- 01Audit the alarm historyIdentified 38 candidate tags responsible for over 80% of acknowledged-and-cleared events.
- 02Train a single anomaly modelMultivariate model on the reactor unit, validated against historical real upsets.
- 03Replace nuisance alarms one block at a timeEach retirement was reviewed and signed off by operations and HSE.
- 04Operator label loopEvery model alert is labelled true/false at close-out; labels feed the next retrain.
Who uses it, and where it fits in the day.
Used continuously by the control-room operator. HSE reviews the labelled alert log weekly. Process engineering owns model retrains.
Quantified, with timeframe and caveats.
- R1False-alarm rate down 71% on the audited unit.
- R2Mean time to detect on real upset events stayed under 7 minutes.
- R3Operator survey showed an 18-point improvement in alert trust.
- 14:22HIGHCMP_042 residual +3.2σ
- 11:08MEDDRY_B drift trend
- 07:41LOWBLR_01 efficiency dip
- 02:15HIGHPUMP_07 cavitation pattern
Operational outcome (proof rule): False-alarm rate on the audited reactor unit fell 71% in three months; mean time to detect on the two real upset events stayed under 7 minutes.
"When the alarm goes now, the crew actually walks to the cell. That hasn't been true here in a long time."
"Alarm fatigue was a top HSE risk for us. The model didn't make the alarms smarter; it let us delete the ones that never said anything."
Relevant for teams trying to…
Chemicals and process teams with alarm-flood problems on continuous units.
- Don't add a new alert layer on top of the old one — replace and retire. Two layers is worse than one.
- Get HSE into the retirement loop on week one. They're the gate, not a reviewer at the end.
- Label every alert. The model gets worse without it.
Talk to an expert about a similar use case.
Tell us your unit and your KPI. We'll come back with what data you'd need and a realistic timeline based on Specialty Chemicals Co.'s rollout.