EVIDENCE REPORT
Report ID: ER-2025-NSM-003
Version: 4.4
Generated: 2025-10-16

Asset Information

Asset ID: MDB-003
Type: Bearing
Description: Main Drive Bearing #3
Location: Hot Strip Mill Line 2
Client: Northbrook Steel Mill
Assessment Date: 2025-10-14

Decision Summary

INVESTIGATE
Continued operation is not defensible under current conditions without immediate investigation.
Planned intervention is recommended within the next maintenance window.

Assessment Results

43.2%
Stability Margin
0.86
Decision Confidence
0.58
ROR
0.47
SDI

Fault Pattern: TYPE A

Metrics increase with degradation. This pattern is characteristic of bearing faults where vibration energy, spectral indicators, and stability loss progress together.

Operator Current Value Baseline Change Status
RMS Energy 2.34 g 0.82 g +185% ELEVATED
Spectral Kurtosis 8.7 3.2 +172% ELEVATED
Negentropy 0.94 0.31 +203% CRITICAL
Envelope Kurtosis 12.4 4.1 +202% CRITICAL

Decision Operators

Operator Value Threshold Interpretation
ROR (Regime Occupancy Ratio) 0.58 0.50 Operating in degraded regime >50% of time
PNR (Point of No Return) Not crossed 25% Reversible. Distance to threshold: 18.2%
SDI (Signed Degradation Index) 0.47 0.50 Approaching critical threshold

Validation Evidence

Confound Check

PASS

r = 0.23
No concerning correlation with load or temperature.

Data Quality

PASS

14,400 samples analyzed
No gaps or anomalies detected.

Pattern Consistency

PASS

TYPE A directionality confirmed.
All operators moving in expected direction.

Recommendation

Immediate Actions Required

Rationale: Current stability margin (43.2%) places this asset in the INVESTIGATE zone. While the Point of No Return has not been crossed, continued degradation at the observed rate would cross the PNR threshold within 2-3 weeks. Intervention now enables planned maintenance vs. emergency response.

Scope & Limitations

This assessment evaluates operational defensibility under observed conditions. It does not replace OEM design limits or safety interlocks. The determination is based on vibration data collected from the asset-mounted accelerometer and analyzed using SimGen's physics-based stability operators.

What this report does NOT include:
This report focuses on operational defensibility and decision support. Detailed diagnostic plots and raw sensor analytics are available in the technical appendix when required.