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AlarmManagementEvents¤

Analyze alarm signals following ISA-18.2 alarm management principles.

Module: ts_shape.events.production.alarm_management Guide: OEE Analytics

When to Use¤

Use for ISA-18.2 compliant alarm management. Identifies chattering alarms, standing alarms, and alarm frequency patterns that indicate system health or nuisance alarm issues. Regular alarm rationalization is critical — operators who receive too many alarms become desensitized, leading to missed critical events.

Quick Example¤

from ts_shape.events.production.alarm_management import AlarmManagementEvents
import pandas as pd
import numpy as np

np.random.seed(42)
df = pd.DataFrame({
    "timestamp": pd.date_range("2024-01-01 06:00", periods=500, freq="30s"),
    "high_temp_alarm": np.random.choice([True, False], size=500, p=[0.15, 0.85]),
    "low_pressure_alarm": np.random.choice([True, False], size=500, p=[0.05, 0.95]),
})

alarms = AlarmManagementEvents(df, timestamp_column="timestamp")
freq = alarms.alarm_frequency(window="1h")
chattering = alarms.chattering_detection(min_transitions=5, window="10m")
standing = alarms.standing_alarms(min_duration="1h")
print(freq.head())

Key Methods¤

Method Purpose Returns
alarm_frequency(window='1h') Count alarm activations per time window to identify alarm flood periods DataFrame with window and activation count per alarm
alarm_duration_stats() Compute statistics on how long each alarm stays active (ON duration) DataFrame with min, mean, max, and percentile durations
chattering_detection(min_transitions=5, window='10m') Detect chattering alarms that toggle rapidly within a short window DataFrame of chattering alarm instances with transition count
standing_alarms(min_duration='1h') Find alarms that remain active beyond a threshold, indicating stale or ignored alarms DataFrame of standing alarm intervals

Tips & Notes¤

Target fewer than 6 alarms per operator per hour

ISA-18.2 recommends a manageable alarm rate. Use alarm_frequency to check if your plant exceeds this guideline and prioritize chattering alarms for rationalization.

Related modules

See Also¤