Failure Mode
Definition
The specific manner in which a component, subsystem, or system fails to perform its intended function or performs it in an unintended way. A failure mode describes the observable manifestation of a failure — what goes wrong — rather than why it goes wrong (failure cause) or what happens as a result (failure effect). Each functional failure may have multiple failure modes.
Context
The central entity in FMEA and RCM analysis. Failure modes are the building blocks of risk assessment — each one is scored for severity, occurrence, and detection to produce an RPN. In Reliatic, failure modes are stored in the 'failure_modes' table with soft-delete support and are associated with specific assets.
Examples
- A centrifugal pump has failure modes including: external leakage, internal leakage, failure to start, failure to stop, abnormal vibration, reduced output, and seized/locked.
- A heat exchanger tube bundle failure mode is 'through-wall perforation' — distinct from its cause (erosion-corrosion) and its effect (process fluid contamination).
Applicable Standards
- IEC 60812:2018
- ISO 14224:2016
- SAE JA1012
Related Terms
The consequence of a failure mode on the operation, function, or status of the item and the system. Failure effects describe what happens when the failure mode occurs, traced from the local effect on the component through the system level to the end effect on the plant, safety, and environment. Effects must be described assuming no detection or compensating provisions are in place.
Failure CauseThe underlying reason or mechanism that initiates the process leading to a failure mode. A failure cause is the root-level factor — design deficiency, material defect, manufacturing flaw, operational condition, degradation mechanism, or human error — that creates the conditions for the failure mode to manifest. Each failure mode may have multiple independent causes.
Failure Mode and Effects Analysis(FMEA)A systematic, proactive methodology for evaluating a process, product, or design to identify all possible failure modes, determine their effects on system performance, rank them by risk priority, and recommend actions to reduce or eliminate the highest risks. FMEA examines each component's potential failure modes, their causes, effects at local/system/end levels, current controls, and risk priority numbers.
Risk Priority Number(RPN)A numerical value that ranks the risk associated with a failure mode by multiplying three independently scored factors: Severity (impact of the failure), Occurrence (likelihood of the failure happening), and Detection (likelihood of detecting the failure before it reaches the end user or causes harm). RPN ranges from 1 to 1,000, where higher values indicate greater risk priority.
Damage MechanismA specific process or phenomenon that causes degradation of material properties, leading to eventual failure of equipment. Damage mechanisms include corrosion (uniform, localized, galvanic), erosion, fatigue, creep, hydrogen damage, stress corrosion cracking, embrittlement, and other metallurgical or environmental attack modes. API 571 catalogues over 60 damage mechanisms relevant to refining and petrochemical equipment.
ISO 14224Petroleum, petrochemical and natural gas industries — collection and exchange of reliability and maintenance data for equipment. This standard defines a taxonomy for equipment classification, failure mode coding, and data fields required for reliability analysis. It provides a common language for recording failure events across organizations and installations.
Where this appears in Reliatic
This concept is used in the FMEA & Risk module.