Anomaly Formula: Amount By Min

What it does:
This rule compares your most recent usage value with the lowest value in your prior history. If the absolute difference between them meets or exceeds your threshold and the change direction matches your setting, you’ll receive an alert.

When to use it:
Catch situations where your usage suddenly climbs well above your usual low water mark or plunges far below it. This is ideal for spotting emerging cost trends or unintended deletions.

Mathematical Formula:

Let:

• L = Latest Value
• M = Min of previous values
• T = Threshold
• D = |L − N| (absolute difference)

Anomaly Condition:

D = |L − M| ≥ T

Direction Validation (based on Change Type): 

• If Change Type = Increased, condition is valid only if  L > M
• If Change Type = Decreased, condition is valid only if  L < M
• If Change Type = Any, direction check is not required

Outcomes:

❌ Anomaly Detected → D ≥ T and direction matches Change Type
☑️ Skipped → D ≥ T, but direction does not match Change Type
✅ Normal → D < T

Examples:

Example 1

Change Type: Increased
Threshold: 30
History: 100, 120, 11

• If Latest Value = 125
  Result: Normal ✅
  Explanation:
  Min: 100
  Change: 125 − 100 = 25
  Absolute Difference (25) < Threshold (30)

• If Latest Value = 150
  Result: Anomaly Detected ❌ 
  Explanation:
    Min: 100
    Change: 150 − 100 = 50
    Absolute Difference (50) ≥ Threshold (30)

• If Latest Value = 90
  Result: Skipped ☑️ 
  Explanation:
    Min: 100
    Change: 90 − 100 = −10
    Absolute Difference (10) < Threshold (30)
    But direction = Decrease → does not match “Increased”

Example 2
Change Type: Decreased
Threshold: 35
History: 300, 320, 310

• If Latest Value = 280
  Result: Normal ✅ 
  Explanation:
    Min: 300
    Change: 280 − 300 = −20
    Absolute Difference (20) < Threshold (35)

• If Latest Value = 250
  Result: Anomaly Detected ❌ 
  Explanation:
    Min: 300
    Change: 250 − 300 = −50
    Absolute Difference (50) ≥ Threshold (35)

• If Latest Value = 360
  Result: Skipped ☑️ 
  Explanation:
    Min: 300
    Change: 360 − 300 = 60
    Absolute Difference (60) ≥ Threshold (35)
    But direction = Increase → does not match “Decreased”

Example 3
Change Type: Any
Threshold: 40
History: 200, 180, 190

• If Latest Value = 210
  Result: Normal ✅ 
  Explanation:
    Min: 180
    Change: 210 − 180 = 30
    Absolute Difference (30) < Threshold (40)

• If Latest Value = 250
  Result: Anomaly Detected ❌
  Explanation:
    Min: 180
    Change: 250 − 180 = 70
    Absolute Difference (70) ≥ Threshold (40)