Failure Code Cheat Sheet

Canonical failure codes for common asset classes. Pick the closest match. Write the code AND a one-line description. This is what turns a "broken bearing" into feedback the cycle can use.

Companion to: Fix the System, Chapter 9. Note: These codes follow the ISO 14224 taxonomy with practical simplifications. Your plant's CMMS may use different code numbers — map these categories to your local codes in the spreadsheet on the back of this sheet. Posted where: taped above every CMMS terminal and on every crew-lead clipboard.

BEARINGS

• B-101 — Bearing wear (normal end-of-life)
• B-203 — Bearing wear, radial play exceeded
• B-205 — Bearing wear, axial play exceeded
• B-301 — Bearing seizure / failure in service
• B-401 — Bearing contamination (water, process fluid, foreign particle)
• B-501 — Bearing lubrication failure (loss of grease/oil, wrong grease, over/under-greasing)
• B-601 — Bearing misalignment damage (spalling, brinelling)

SEALS

• S-101 — Seal wear (normal end-of-life)
• S-105 — Mechanical seal, face-to-face leakage
• S-107 — Mechanical seal, secondary leakage (O-ring)
• S-201 — Lip seal, wiper lip damage
• S-301 — Seal damage from shaft runout / misalignment
• S-401 — Seal damage from improper installation
• S-501 — Seal damage from wrong seal selection for service

COUPLINGS / SHAFTS / ALIGNMENT

• H-042 — Shaft misalignment, parallel offset
• H-045 — Shaft misalignment, angular
• H-102 — Coupling wear (elastomer, grid, gear)
• H-201 — Coupling failure in service (sheared key, broken bolt)
• H-301 — Shaft surface damage (pitting, scoring)
• H-401 — Shaft bearing-journal wear
• H-501 — Shaft dimensional deviation (bent, out of spec)

LUBRICATION

• L-101 — Oil contamination (water, particulates, wrong viscosity)
• L-201 — Oil level low
• L-301 — Grease pump / distributor failure
• L-401 — Wrong lubricant used
• L-501 — Lubricant degradation (heat, age, oxidation)

ELECTRICAL

• E-101 — Motor winding failure (insulation breakdown)
• E-201 — Motor bearing electrical pitting
• E-301 — Contactor / relay failure
• E-401 — VFD fault (over-current, over-voltage, temperature)
• E-501 — Control wiring fault (loose, broken, shorted)
• E-601 — Breaker / fuse failure
• E-701 — Grounding deficiency

INSTRUMENTATION

• I-101 — Sensor drift out of calibration
• I-201 — Sensor failure (no signal)
• I-301 — Transmitter failure
• I-401 — Sensor contamination / fouling

PROCESS / FLUID

• P-101 — Process fluid contamination
• P-201 — Process pressure excursion
• P-301 — Process temperature excursion
• P-401 — Flow blockage (filter, strainer, line)

STRUCTURAL / MECHANICAL

• M-101 — Fastener failure (shear, loosening, thread strip)
• M-201 — Crack in pressure boundary
• M-301 — Corrosion (external)
• M-305 — Corrosion (internal, process-side)
• M-401 — Erosion / abrasion wear

HUMAN / PROCEDURE

• U-101 — Operator-induced damage (wrong procedure, over-speed, over-pressure)
• U-201 — Maintenance-induced damage (improper reassembly, wrong torque)
• U-301 — Missed PM / inspection

How to use this sheet

1. Pick the closest code. If multiple modes are present, list multiple codes. 2. Always write both the code AND a one-line description. Just the code number is not enough. Future-you (or a different planner) will need the description. 3. If no code fits, write "X-999" and describe the mode fully. Your plant can add new codes from recurring X-999 entries. 4. Do NOT use "M-999" or "B-999" to mean "I don't know." If you don't know the failure mode, write that in the notes field. Unknown is information; a wrong code is noise.

Back of sheet — map to your local CMMS codes

From Fix the System by Ivan Getov. Companion to Chapter 9: Close Out and Learn. getov.xyz/toolkit/fix-the-system/ch09/failure-code-cheat-sheet. Free. No email required.