FMEA

The aim of FMEA is to detect potential failures at an early stage and assess their effects. This allows countermeasures to be taken before the failure actually occurs. The main objectives are:

• Failure prevention: reducing costs and time through prevention.

• Improving safety: avoiding risks to users and systems.

• Increasing quality: ensuring consistent processes and products.

There are different types of FMEA, which are used depending on the focus:

Type	Description	Application examples
System FMEA	Examines possible failures at system level and their effects on the overall system.	Vehicles, machines, electronic systems
Design FMEA	Analyses potential failures in product development or design.	Engine parts, electronic components
Process FMEA	Assesses risks in production or manufacturing.	Assembly lines, painting processes
Service FMEA	Analyses failures in services and their effects on customers.	Customer support, maintenance processes

FMEA follows a structured sequence divided into several steps:

Steps of an FMEA

• System analysis: definition of the product or process and identification of the relevant functions.

• Failure identification: listing possible failures and their causes.

• Risk assessment: assessment of the failures on the basis of three criteria: probability of occurrence (O)

• Severity for the customer (S; German: B)

• Probability of detection (D; German: E)

• Risk priority number (RPN; German: RPZ): calculated by multiplying the three criteria (RPN = O × S × D).

• Action planning: defining countermeasures to reduce the risks.

• Follow-up: checking the effectiveness of the measures implemented.

The risk assessment is based on the risk priority number (RPN). The RPN shows which failures are particularly critical and should be dealt with as a priority.

Criterion	Rating scale	Description
Probability of occurrence (O)	1 (very unlikely) to 10 (very likely)	How likely is it that the failure will occur?
Severity (S)	1 (low) to 10 (very high)	How serious are the effects of the failure?
Probability of detection (D)	1 (very likely to be detected) to 10 (very unlikely to be detected)	How likely is it that the failure will be detected before delivery?

Using FMEA offers numerous advantages:

• Early detection of failures: identification of potential weak points before they occur.

• Cost savings: reduction of failure costs through preventive measures.

• Compliance with standards: support in complying with quality and safety standards (e.g. ISO 9001, IATF 16949).

• Systematic approach: structured analysis ensures transparency and traceability.

• Time required: a thorough FMEA requires considerable resources.

• Data availability: precise analyses require detailed information.

• Subjectivity: the rating of the criteria can vary and often depends on the experience of those involved.

Feature	FMEA	FTA (fault tree analysis)
Approach	Bottom-up (individual failure → overall risk)	Top-down (system risk → individual failure)
Focus	Individual failures and their causes	Overall system and potential failure chains
Applications	Products, processes	Complex systems
Effort	Higher for detailed analyses	Lower for simple analyses

• In which industries is FMEA used? FMEA is used in almost all industries, including automotive, electronics, aerospace, medical technology and mechanical engineering.

• What is the risk priority number (RPN)? The RPN is a measure for prioritising risks. It is calculated by multiplying the ratings for probability of occurrence, severity and probability of detection.

• How often should an FMEA be carried out? An FMEA should be carried out regularly and whenever there are changes to the product or process.

• Which software tools support FMEA? There are specialised tools such as APIS IQ, PTC Windchill and Excel-based solutions that make the process easier.

FMEA is a proven method for preventing failures and increasing quality. It enables companies to identify risks systematically and save costs and time through preventive measures. Whether in product development or process optimisation, FMEA is an indispensable tool for companies that want to meet the highest safety and quality standards.