ISO 14224 is an international standard for collecting and exchanging reliability and maintenance data for equipment in the petroleum, petrochemical, and natural gas industries. It provides a standardized taxonomy for classifying equipment, failure modes, and failure causes.

MTBF (Mean Time Between Failures) is the predicted elapsed time between inherent failures of a mechanical or electronic system during normal operation. It is typically expressed in hours or years and is a key metric in reliability engineering.

How does ISO 14224 classify failure modes?

ISO 14224 uses a hierarchical taxonomy with equipment class, subunit, and maintainable item levels. Failure modes describe how equipment fails (e.g., leakage, vibration, overheating), while failure mechanisms explain why it fails (e.g., corrosion, fatigue, erosion).

What is the difference between failure mode and failure cause?

A failure mode describes the way a failure is observed (e.g., abnormal vibration, leakage, failure to start). A failure cause (or mechanism) describes the underlying reason (e.g., bearing wear, seal degradation, corrosion). ISO 14224 distinguishes both for proper root cause analysis.

How can failure data improve maintenance strategy?

By analyzing failure modes and their frequencies, maintenance can shift from reactive to predictive. High-frequency failures may justify condition monitoring, while age-related failures support time-based replacement. ISO 14224 data enables reliability-centered maintenance (RCM) decisions.

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Equipment Failure Classifier

Classify equipment failures per ISO 14224. Select equipment type and observed symptoms to identify failure modes, typical MTBF ranges, and maintenance strategies.

ISO 14224Reliability DataMTBF Reference

Equipment Type

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Observed Symptoms (select all that apply)

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Classification Results

Failure Mode Hierarchy

ISO 14224 defines a structured hierarchy for recording reliability data:

Equipment class — e.g. pump, compressor, motor
Subunit — e.g. rotating equipment → bearing subunit
Maintainable item — e.g. bearing, seal, impeller
Failure mode — observed effect (vibration, leakage, etc.)
Failure mechanism — root cause (fatigue, corrosion, erosion)

Common Failure Modes per ISO 14224

Code	Failure Mode	Description
FTS	Fail to start	Equipment does not start on demand
STP	Spurious stop	Unexpected shutdown during operation
ELU	External leakage — utility	Leakage of utility fluids
ELP	External leakage — process	Leakage of process medium
INL	Internal leakage	Leakage across internal barriers
VIB	Abnormal vibration	Vibration exceeding acceptable limits
OHE	Overheating	Excessive temperature
LOO	Low output	Reduced performance (flow, pressure)
NOI	Abnormal noise	Unusual sound during operation
ERO	Erratic output	Fluctuating or unstable performance

Note: MTBF values shown are typical industry ranges from OREDA and similar databases. Actual MTBF depends on operating conditions, maintenance quality, and equipment design.

Equipment Failure Classifier | ISO 14224 | Reliability Data

Published by Nikolai Shelkovenko on February 15, 2026 February 15, 2026

Classification Results

Failure Mode Hierarchy

Common Failure Modes per ISO 14224