Service · Asset Reliability · Failure Mode Engineering

Understand how your
assets fail. Build programmes
that prevent it.

Optimal's Asset Reliability practice applies the full discipline of failure mode engineering — ISO 14224 taxonomy, industry failure rate databases, FMECA and structured root cause analysis — to build evidence-based reliability programmes across oil & gas, nuclear, chemical and mining operations worldwide.

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Service Scope

ISO 14224 failure taxonomy — equipment, failure mode, mechanism and cause classification

OREDA, nuclear, chemical and mining industry failure rate database application

FMECA to IEC 60812, MIL-STD-1629A, SAE ARP5580 and BS EN 60812

Root cause analysis — TapRooT®, Apollo, FTA and structured Fishbone methodology

Defect elimination programmes — chronic loss identification and permanent corrective action

Reliability outputs structured for direct CMMS integration and programme governance

ISO 14224 · IEC 60812 · MIL-STD-1629A · SAE ARP5580

Oil & Gas · Nuclear · Chemical · Mining · Power

Rotating · Static · E&I · Structural

UK · North Sea · Sub-Saharan Africa · West Africa

The Foundation — ISO 14224

"Petroleum, petrochemical and natural gas industries — Collection and exchange of reliability and maintenance data for equipment."

ISO 14224:2016 — International Standard for Reliability Data Collection

Every failure has a precise location in the taxonomy. ISO 14224 defines a structured hierarchy — equipment class, sub-unit, component — against which failure modes, mechanisms and causes are systematically recorded. This rigour is what separates engineering evidence from engineering opinion.

Failure modes are not symptoms. ISO 14224 distinguishes between the failure mode (the way a function is lost), the failure mechanism (the physical, chemical or metallurgical process), and the failure cause (the initiating factor). Correct classification at each level is essential for valid FMECA and effective RCA.

The standard enables inter-organisational benchmarking. Data recorded to ISO 14224 can be compared against industry databases — OREDA, nuclear T-Book, CCPS chemical data — giving Optimal access to failure rate evidence extending across millions of component-years of operation.

It underpins every upstream service Optimal delivers. RCM studies, FMECA, RBI and RAM modelling all depend on accurate failure mode characterisation. ISO 14224 is the common language through which engineering data translates into maintenance decisions and risk assessments.

The Reliability Challenge

Most asset failures are entirely predictable.

The majority of unplanned downtime events experienced by asset-intensive operators are not random. They are the consequence of failure modes that were already documented — in equipment history, in industry databases, in the collective experience of the sector — but never systematically translated into preventive action.

Without a structured failure mode framework, maintenance programmes default to OEM schedules, tribal knowledge and reactive response. The result is consistent: excessive planned maintenance on low-risk equipment, insufficient attention to high-consequence failure modes, and a pattern of repeat failures that management treats as inevitable but engineers recognise as preventable.

Optimal's approach treats asset reliability as an engineering discipline, not a maintenance scheduling exercise. Every failure mode is identified, classified and allocated a maintenance response calibrated to its consequence and detectability — with industry failure rate data providing the quantitative foundation for prioritisation decisions.

Failure modes not classified to standardMaintenance history recorded as symptoms rather than ISO 14224 failure modes — preventing cross-asset analysis, benchmarking and failure rate calculation.

No connection to industry failure databasesMaintenance strategies developed without reference to OREDA, T-Book or CCPS data — forfeiting decades of sector-specific failure rate evidence in favour of OEM defaults.

FMECA performed at insufficient depthEquipment-level analysis without sub-unit and component-level failure mode identification — missing the failure mechanisms that drive the majority of unplanned events.

RCA findings not closing the loopRoot cause investigations completed but corrective actions not embedded into the maintenance programme — allowing failure recurrence and eroding organisational confidence in the process.

Defects managed, not eliminatedChronic failure modes treated as operational reality rather than engineering problems — absorbing maintenance resource without addressing root cause and compounding reliability losses year on year.

ISO 14224 Classification Framework

Four levels of failure precision.

ISO 14224 structures failure data across a four-level hierarchy — from equipment class through to root cause. Each level carries distinct engineering significance and drives a different element of the reliability programme.

ISO 14224 · Level 1

Equipment Taxonomy

Equipment class, sub-unit and component structured to ISO 14224 Annex A — covering rotating machinery, static equipment, electrical systems, E&I and structural assets. The taxonomy establishes the functional boundary for failure analysis and enables aggregation across similar equipment types.

Boundary Definition

ISO 14224 · Level 2

Failure Mode

The observable way in which a function is lost — leakage external (LKE), fails to start (FTS), high output (HIO), structural deficiency (STD). ISO 14224 defines a standardised failure mode library enabling cross-asset and cross-operator comparability of failure data at the mode level.

Functional Impact

ISO 14224 · Level 3

Failure Mechanism

The physical, chemical or metallurgical process by which the failure mode manifests — corrosion, erosion, fatigue, cavitation, seal degradation, mechanical wear. Failure mechanism identification is the bridge between observable failure mode and actionable maintenance task selection in FMECA.

Engineering Cause

ISO 14224 · Level 4

Failure Cause

The initiating factor — design deficiency, manufacturing defect, installation error, operational misuse, maintenance error or ageing. Cause identification is the domain of root cause analysis and defect elimination. Without precise cause attribution, corrective actions remain symptomatic rather than systemic.

RCA Target

ISO 14224 Standardised Failure Mode Library — Selected Examples

The standard defines a controlled vocabulary of failure modes applicable across equipment classes. Consistent application enables failure rate calculation, FMECA scoring and cross-operator database comparison.

Code	Failure Mode	Category	Typical Failure Mechanism	FMECA Significance
LKE	Leakage — External	Process	Corrosion, erosion, flange fatigue, seal degradation, mechanical damage to containment	Safety-critical on hydrocarbon-bearing plant; drives condition-based inspection frequency
FTS	Fails to Start on Demand	On-Demand	Electrical fault, mechanical seizure, instrument failure, control logic error, lubrication failure	Consequence-driven — hidden failure mode on standby equipment requiring proof-test task
FTR	Fails to Run / Spurious Stop	On-Demand	Overheating, vibration exceedance, control signal loss, mechanical failure during operation	Operational consequence — drives condition monitoring task selection for running equipment
HIO	High Output	Instrument	Control valve malfunction, instrument drift, process parameter exceedance, fouling	Process safety relevance; calibration interval and instrument health monitoring driven
LOO	Low Output	Instrument	Blockage, wear, cavitation, pump degradation, fouling of heat transfer surfaces	Production loss consequence — condition monitoring tasks aligned to degradation mechanism
STD	Structural Deficiency	Structural	Fatigue cracking, overload, corrosion under insulation (CUI), weld defect propagation	Safety-critical; drives RBI inspection planning and fitness-for-service assessment intervals
AIR	Abnormal Instrument Reading	Instrument	Sensor drift, calibration loss, signal conditioning fault, process connection blockage	Safety system reliability — functional testing interval and proof-test coverage driven
SPO	Spurious Operation	On-Demand	Control logic error, electrical noise, signal fault, software defect, incorrect permissive	Hidden failure on safety systems; functional test frequency determined by PFD target

Industry Failure Rate Databases

Decades of failure data. Applied to your assets.

Optimal's FMECA and reliability programmes draw on the full hierarchy of industry failure rate databases — from the OREDA offshore equipment dataset through to sector-specific nuclear, chemical and mining references. Each source is selected on the basis of equipment class match, operating environment relevance and statistical confidence.

Primary Reference — Ranked 1

ISO 14224 Taxonomy Foundation

The international standard that defines equipment classification, failure mode vocabulary and data collection methodology — the common framework within which all industry failure rate databases are structured and against which Optimal records client reliability data for future benchmarking.

All Sectors

Primary Reference — Ranked 2

OREDA — Offshore & Onshore Reliability Data

The pre-eminent industry failure rate database for oil & gas equipment — compiled across decades by major operators including Equinor, Shell, TotalEnergies and bp. OREDA provides failure rates, repair times and failure mode distributions for rotating machinery, static equipment, subsea systems and E&I by equipment class and operating environment.

Oil & Gas · Offshore · Onshore

Sector Reference — Ranked 3

Nuclear — T-Book & NUREG/CR Series

The T-Book (Reliability Data of Components in Nordic Nuclear Power Plants) and USNRC NUREG/CR series provide failure rate data for safety-classified electrical, mechanical and instrumentation components operating within nuclear licensing envelopes — essential for FMECA where IEC 61508 SIL determination is required.

Nuclear · Safety-Classified

Sector Reference — Ranked 4

Chemical — CCPS / AIChE Process Equipment

The Center for Chemical Process Safety (CCPS) Guidelines for Process Equipment Reliability Data provides failure rates and failure mode distributions for process plant equipment — vessels, heat exchangers, pumps, valves and instrumentation — in chemical and petrochemical service environments.

Chemical · Petrochemical · Pharma

Sector Reference — Ranked 5

Mining — Equipment Failure Mode Databases

Mining-sector failure mode references — including OEM data, SMRP benchmarking and commodity-specific reliability databases for crusher, conveyor, HPGR, mill, pump and surface/underground mobile equipment — applied where ISO 14224 and OREDA classifications do not cover the specific mining asset class.

Mining · Multi-Commodity

Database selection is an engineering decision, not a default. Optimal selects failure rate references on the basis of equipment class match, operating environment parity and the statistical confidence of the underlying dataset. Where no published database provides an adequate match, Optimal uses client operational history — structured to ISO 14224 — as the primary failure rate source, supplemented by expert engineering judgement.

Failure Mode, Effects & Criticality Analysis

FMECA — the analytical engine of reliability.

FMECA is the structured process through which every identified failure mode is evaluated for severity, probability of occurrence and detectability — producing a criticality ranking that directs maintenance investment and engineering attention to where consequence is highest and risk reduction is greatest.

Optimal conducts FMECA to the appropriate international standard for the sector and regulatory environment of each engagement. The analysis proceeds at sub-unit and component level — not equipment level — to ensure that failure modes with catastrophic consequences but low visibility at the system level are captured and appropriately addressed.

The FMECA output is a structured asset criticality register: each failure mode ranked by Risk Priority Number (RPN) or criticality matrix score, with maintenance task type, frequency and acceptance criteria traceable to the analytical rationale. Every decision is documented and auditable.

IEC 60812 — Analysis Techniques for System Reliability: FMEA ProcedureIEC 60812

MIL-STD-1629A — Military Standard: Failure Mode and Effects Criticality AnalysisMIL-STD-1629A

SAE ARP5580 — Recommended Failure Modes and Effects Analysis PracticesSAE ARP5580

BS EN 60812 — UK/European Adoption of IEC 60812 FMEA ProcedureBS EN 60812

Root Cause Analysis

Finding the cause, not treating the symptom.

Root cause analysis is the investigation process applied when a failure has occurred — determining not only what failed, but why the failure occurred and what systemic conditions allowed it. Correctly conducted, RCA prevents recurrence and drives actionable change to the maintenance programme and engineering standards.

Methodology 01

TapRooT® Root Cause Analysis

The TapRooT® system is a structured, evidence-driven investigation methodology that maps causal factors through a proprietary root cause tree — identifying systemic management system deficiencies, not merely proximate equipment failures. Widely applied in high-consequence industries including nuclear, oil & gas and aviation where regulatory rigour demands documented investigation trails.

Event and causal factor charting

Root cause tree analysis

Corrective action development and tracking

Management system gap identification

Methodology 02

Apollo Root Cause Analysis

Apollo RCA (Reality Charting) employs a cause-and-effect relationship mapping approach — constructing a visual chart of the causal chain from the problem statement back through contributing causes to systemic root causes. The methodology emphasises consensus-building among cross-functional investigation teams and produces solutions that address causes at every level of the causal chain.

Problem definition and impact quantification

Cause-and-effect reality chart construction

Solution verification against causal chain

Action ownership and closure tracking

Methodology 03

5-Whys & Ishikawa (Fishbone) Analysis

For failure events of moderate complexity, the structured 5-Whys interrogation and Ishikawa cause-and-effect diagram provide rapid, team-driven investigation tools requiring minimal specialist facilitation. The Fishbone diagram organises potential causes across six categories — Machine, Method, Material, Manpower, Measurement and Environment — ensuring systematic coverage of all failure cause domains.

Problem statement definition

Fishbone cause mapping across 6M categories

5-Whys interrogation to systemic cause

Corrective action prioritisation

Methodology 04

Fault Tree Analysis (FTA)

FTA is a deductive, top-down analysis technique that models the logical relationship between a defined top-level failure event and its underlying causes using Boolean logic gates. FTA is the preferred approach for complex, multi-cause failure events — particularly in safety system analysis, SIL verification and nuclear PSA — where quantitative probability assessment of the top event is required.

Top event definition and boundary conditions

Boolean logic gate tree construction

Minimal cut set identification

Quantitative probability calculation (where data permits)

RCA must close the loop. An investigation report without verified corrective actions is an administrative exercise. Optimal's RCA engagements always conclude with structured corrective actions embedded into the client's maintenance programme, engineering standards or operating procedures — with defined owners, deadlines and verification criteria. The maintenance programme is updated to reflect the findings before the engagement closes.

Defect Elimination

Stop managing failure.
Eliminate it.

Defect elimination is the proactive reliability discipline that targets chronic failure modes — those failure events that recur with regularity, each time consuming maintenance resources, each time generating a work order, each time classified as normal operational reality. They are not normal. They are engineering problems with engineering solutions.

A structured defect elimination programme begins with chronic loss identification — applying Pareto analysis to the maintenance work order history to isolate the 20% of failure modes generating 80% of corrective maintenance cost and production loss. Each chronic failure is then subjected to a formal RCA, and the resulting corrective actions are tracked to verified closure against a measurable improvement target.

Chronic Loss IdentificationPareto analysis of CMMS work order history — isolating repeat failure modes by cost, frequency and production impact to establish the defect elimination programme scope and prioritisation.

Failure Mode Re-ClassificationEach chronic failure mode re-classified to the full ISO 14224 taxonomy — failure mode, mechanism and cause — to ensure that the corrective action addresses the root cause, not a downstream symptom.

Root Cause InvestigationFormal RCA conducted for each prioritised chronic failure mode — using TapRooT®, Apollo or structured Fishbone methodology according to complexity — with findings validated by cross-functional review.

Permanent Corrective ActionCorrective actions developed to address root cause — engineering modifications, operating procedure changes, maintenance task updates or training interventions — each with a named owner, deadline and measurable success criterion.

Verification & CMMS UpdateCorrective actions verified against the target failure mode recurrence rate. The maintenance programme and CMMS are updated to reflect the elimination — ensuring the improvement is institutionalised rather than remaining in an investigation report.

Continuous Improvement IntegrationDefect elimination embedded as a standing element of the operational reliability programme — with monthly chronic loss reviews, a rolling elimination register and a governance process connecting field findings to engineering standards.

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Engagements · Evidence

Failure mode engineering delivered in practice.

Selected Optimal engagements where structured failure mode analysis, FMECA and root cause methodology were applied to deliver measurable reliability outcomes across oil & gas, nuclear, mining and utilities sectors.

Oil & Gas · North Sea · Offshore

Major Offshore Operator — Two-Platform Engagement

North Sea Power Generation & Process — RCM & Failure Mode Study

Two-platform RCM study covering all rotating and static equipment — failure mode identification to ISO 14224 across power generation, compression and process systems, with OREDA failure rate benchmarking applied throughout. CMMS-ready maintenance schedules delivered as the primary output.

Offshore platforms covered — rotating machinery, static equipment, E&I and process systems included within study boundary

ISO 14224

Full failure mode taxonomy applied — failure mode, mechanism and cause classified for every asset within scope

OREDA

Offshore failure rate database applied to validate maintenance task intervals and calibrate criticality scoring

Mining · Multi-Commodity · Global

Global Mining Group — Group-Wide Programme

Diamond, Platinum, Coal & Iron Ore — Failure Mode & Maintenance Strategy

Group-wide maintenance strategy and asset management capability programme across diamond, platinum, coal and iron ore operations — failure mode identification and FMECA applied to standardise best practice across a complex multi-commodity portfolio with differing equipment classes, operating environments and regulatory frameworks.

Commodity sectors covered — diamond, platinum, coal and iron ore operations each with distinct failure mode profiles

Group

Group-wide standardisation of failure mode classification enabling cross-site benchmarking and best-practice transfer

FMECA

Criticality analysis applied across equipment classes — crusher, conveyor, mill, pump, electrical and instrumentation systems

View case study →

Nuclear · Decommissioning

Major Nuclear Decommissioning Facility — UK

Nuclear Materials Management & Spare Parts Reliability Programme

Materials management strategy and spare parts rationalisation programme for a major nuclear decommissioning facility — failure mode analysis applied to align inventory holdings to maintenance requirements and decommissioning milestones. Nuclear failure rate references (T-Book / NUREG/CR) applied to validate critical spare classifications and safety-significant component identification.

Nuclear

Safety-classified equipment failure mode analysis — T-Book and NUREG/CR database references applied throughout

SIL

Safety Integrity Level assessment integrated with failure mode analysis for safety-classified instrumentation and control systems

Decom

Maintenance requirements aligned to decommissioning milestones — failure mode analysis informing end-of-life strategy

View case study →

Public Sector · Water Treatment · South Africa

Major District Municipality — KwaZulu-Natal

Water Treatment Plant — Asset Tactics & Failure Mode Development

Three-phase asset tactics development programme covering 33 critical asset types across water treatment facilities serving four local municipalities — failure mode identification, consequence classification and FMECA applied to mechanical, electrical and instrumentation equipment, with maintenance strategies structured for direct CMMS upload and aligned to a comprehensive fixed asset register.

Critical asset types analysed — mechanical, electrical and instrumentation systems across water treatment infrastructure

Programme phases — failure mode identification, consequence assessment and CMMS-ready maintenance task development

Local municipalities served — one integrated asset reliability programme covering a regional water utility network

View case study →

The ARaaS® Reliability Toolbox

Failure mode engineering inside a continuous service model.

Optimal's asset reliability services are delivered within the ARaaS® framework — a structured programme that compounds reliability improvements year on year. FMECA findings inform the maintenance strategy. RCA corrective actions update the programme. Defect elimination targets feed back into FMECA re-scoring. The loop is closed, continuously.

Explore ARaaS® GARPI™ Benchmark →

Foundation

ISO 14224 Failure Taxonomy & Classification Framework

Database

OREDA · T-Book · CCPS · Mining Failure Databases

Analysis

FMECA to IEC 60812 · MIL-STD-1629A · SAE ARP5580

Investigation

TapRooT® · Apollo RCA · FTA · Fishbone

Elimination

Chronic Loss Pareto · Defect Elimination Register

Output

Criticality Register · CMMS-Ready Task Library

Related Services

Where failure mode engineering connects.

Engage Optimal

Begin with a structured discovery conversation.

Optimal's engagement model begins by understanding your current reliability position — the asset base, the failure mode data available, the gaps in your current programme and the sectors and standards relevant to your operations. No obligation. Clear scope. Measurable outcomes.

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GARPI™ Reliability Benchmark

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Understand how yourassets fail. Build programmesthat prevent it.

Most asset failures are entirely predictable.

Four levels of failure precision.

Decades of failure data. Applied to your assets.

FMECA — the analytical engine of reliability.

Finding the cause, not treating the symptom.

Stop managing failure.Eliminate it.

Failure mode engineering delivered in practice.

Failure mode engineering inside a continuous service model.

Where failure mode engineering connects.

Begin with a structured discovery conversation.

Understand how your
assets fail. Build programmes
that prevent it.

Stop managing failure.
Eliminate it.