Failure Mode, Effects, and Diagnostic Analysis

Also known as: FMEDA

FMEDA is a quantitative reliability analysis method used in functional safety to determine the failure rates, failure modes, and diagnostic coverage of safety-related components, providing the data needed to verify that a safety function meets its target SIL or Performance Level.

Last updated: April 2026

Key Facts

Full name: Failure Mode, Effects, and Diagnostic Analysis
Common acronym: FMEDA
Origin: exida engineers, late 1980s; term coined 1994
Builds on: FMEA (Failure Mode and Effects Analysis)
Primary use: Hardware reliability data for SIL or PL verification
Sectors: Process, automotive, machinery, medical device
Standards: IEC 61508 (Annex C), IEC 62061, ISO 13849, ISO 26262
Outputs: Failure rates per failure mode, diagnostic coverage, useful life
Used to calculate: Safe Failure Fraction (SFF), PFD, PFH
Typical course length: 1 to 2 days
Common audience: Hardware engineers, reliability engineers, FS practitioners
Common software tools: exida exSILentia, IFA SISTEMA

What is FMEDA?

FMEDA extends the classic FMEA process by adding quantitative failure data and diagnostic coverage. For each component in a safety-related system, the analyst identifies possible failure modes, assigns a failure rate to each, classifies the mode as safe or dangerous, and determines whether the system's automatic diagnostics would detect the failure. The analysis produces the inputs needed to calculate Safe Failure Fraction, probability of failure on demand (PFD), and probability of failure per hour (PFH) — the metrics required to verify SIL under IEC 61508. FMEDA is also used to support PL verification under ISO 13849 and ASIL hardware metrics under ISO 26262.

FMEA vs FMEDA

Aspect	FMEA	FMEDA
Scope	Identifies failure modes and effects	Adds quantitative failure rates and diagnostic coverage
Output	Risk priority numbers, qualitative ratings	Failure rates, diagnostic coverage, SFF
Use in functional safety	Hazard identification	SIL or PL hardware verification
Required for	All safety analysis	IEC 61508, IEC 62061, ISO 26262 hardware verification

How FMEDA Relates to Other Standards

FMEDA is referenced explicitly in IEC 61508, IEC 62061, ISO 13849, and ISO 26262 as a method for hardware reliability analysis. The method was developed in the late 1980s by exida engineers and was incorporated into IEC 61508 during the standard's preparation. Today, FMEDA is the dominant method for generating the hardware reliability data required to demonstrate SIL or PL achievement. Component manufacturers increasingly publish FMEDA reports for safety-rated products, allowing system integrators to use vendor data rather than performing their own component-level analysis.

How Functional Safety Training Providers Deliver FMEDA Training

FMEDA training is typically a 1 to 2 day workshop for hardware engineers and reliability engineers, often packaged within broader IEC 61508 hardware engineer programmes. exida runs dedicated FMEDA training as part of its CFSE programme. Some providers offer FMEDA tool-specific training (exSILentia, SISTEMA). Hands-on exercises are essential — most courses run delegates through an FMEDA on a representative safety circuit. An LMS supporting FMEDA training needs cohort scheduling, integration with FMEDA tool exercise files, secure delivery of confidential vendor case studies, identity verification at exam, and verifiable certificates aligned to recognised schemes.

Common Questions

Is FMEDA always required?

For SIL verification under IEC 61508, you need quantitative hardware reliability data, and FMEDA is the standard method to produce it. Other approaches exist (parts-count, field data) but FMEDA is dominant.

Who runs the FMEDA — vendor or integrator?

Both. Component manufacturers run FMEDAs on safety-rated products and publish failure rate data. System integrators run system-level FMEDAs that combine vendor data with their architecture and diagnostic strategy.

How is FMEDA different from FMEA?

FMEA identifies failure modes qualitatively. FMEDA adds quantitative failure rates and diagnostic coverage. FMEA is suitable for hazard analysis; FMEDA is required for SIL or PL hardware verification.

What software is used for FMEDA?

exida exSILentia and IFA SISTEMA are the most widely used. Some companies use custom spreadsheets or proprietary tools. The software automates the calculation of SFF, PFD, and PFH from the underlying component data.

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FMEDA training providers need an LMS built for hardware engineering workshops, FMEDA tool integration, and certification audit trails. Blend-ed runs cohort-based scheduling, secure case study delivery, identity verification at exam, verifiable certificates, and audit-ready records.

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