Functional Safety Analysis using FMEA - FMEA series Chapter 1

Understanding FMEA (Failure Mode Effect Analyses): The Cornerstone of Automotive Safety Analysis 

In the automotive industry, safety is paramount. Every sensor, processor, actuator, and software must work safely to ensure that vehicles operate safely under all conditions. Among the many processes that engineers use to achieve this, the FMEA stands out as one of the most widely adopted and useful methods for identifying and mitigating risk. 

FMEA background 

The Failure Mode and Effects Analysis (FMEA) methodology was first developed by the U.S. Department of Defense in the 1940s and was later adopted by the aerospace industry in the 1960s. The automotive industry began utilizing FMEAs in the 1980s and formally introduced them with the publication of the AIAG FMEA Reference Manual in 1993. Subsequently, the German Association of the Automotive Industry (VDA) released its own reference manual in 1996. In 2019, these two approaches were unified through the publication of the joint AIAG & VDA FMEA Handbook, which replaced the previous individual manuals and established a harmonized global standard for FMEA practices. 

What Is FMEA? 

In short, FMEA helps answer four critical questions: 

1. What can go wrong? 

2. What is the effect? 

3. What can we do to mitigate it? 

4. Are the mitigation measures good enough 

Identifying what can go wrong involves a structured approach to determine the failure modes of components, functions, or processes. 

Determining the effect means assessing the consequences of each failure mode. These effects are not limited to safety concerns - they can also relate to reliability, availability, or quality. Each effect is evaluated and assigned a score (between 1-10) based on its severity. It is likely that safety issues have a higher severity rating. 

Developing mitigation measures is a systematic process to define actions that can either prevent the causes of a failure mode or detect its effects. In both cases, a score (between 1-10) is assigned to the prevention and detection measure. 

Effectiveness of Mitigation Measures – Based on the identified effects, as well as the associated prevention and detection measures, the overall risk can be evaluated. The latest approach in FMEA uses the Action Priority (AP) method to determine and rank the level of risk. The primary objective is to reduce the risk to the lowest possible level. If the risk is found to be high, it can be mitigated through a combination of enhanced detection methods and stronger preventive actions. 

Types of FMEA in Automotive Engineering 

There is not just one type of FMEA - different stages of product development require different perspectives. Each type of FMEA focuses on a specific aspect of the system or process 

1. System FMEA (SFMEA) is conducted at the highest level of abstraction, focusing on how various subsystems and components interact within a complete system. The objective is to understand the consequences of a subsystem failure on the overall system. For example, a malfunction in a vehicle’s camera module could affect the emergency braking system, compromising its ability to detect and respond to obstacles. SFMEA enables engineers to identify appropriate mitigation measures and incorporate design redundancies, such as using Radar in conjunction with a camera, to enhance system reliability and fault tolerance 

2. Design FMEA (DFMEA) examines the system at a detailed design level, including mechanical components and electrical circuits. It focuses on potential design-related weaknesses, such as material defects, electrical overstress, thermal degradation etc. For example, a resistor might overheat under specific load conditions, or a sensor could produce inaccurate readings due to electromagnetic interference. DFMEA allows engineers to enhance product robustness and safety by optimizing component selection, circuit layout, and other design decisions early during the development process.  

3. Process FMEA (PFMEA) shifts the focus from product design to manufacturing and assembly. Even a well-designed product can fail if the production process introduces defects. PFMEA helps teams identify potential process-related failure modes that could lead to product defects, which in turn may impact safety or reliability during operation. By analyzing each step of the manufacturing process, engineers can implement preventive controls to ensure consistent quality, minimize variability, and reduce the risk of failures in the final product. 

4. Software FMEA assesses the reliability and robustness of software design to prevent internal failures. It focuses on identifying potential software-related failure modes that could impact system performance or safety. By analyzing code logic, algorithms, and system interactions, it helps uncover vulnerabilities before deployment. Mitigation measures are then developed to address these risks, improving software stability and fault tolerance. Ultimately, Software FMEA ensures that software components operate reliably within the overall system. 

How to perform an FMEA 

See this blogpost 7-Steps FMEA Process to Perform an FMEA

Modern Trends: Digital and Automated FMEA 

To improve speed while maintaining safety, the industry is increasingly adopting model-based and automated FMEA approaches. By linking FMEA directly to system architecture models, simulation data, and reliability databases, organizations can: 

• Auto-generate FMEA tables from system models 

• Predict failure propagation paths 

• Maintain traceability between design changes and safety documentation 

These advancements are transforming FMEA from a static document into a dynamic safety analysis tool, enabling continuous assurance throughout development. One example is SLIKWORKS, which leverages AI to create and maintain FMEAs, helping engineers ensure that systems remain reliable and safe. 

Conclusion 

FMEA remains one of the most powerful tools in the automotive safety engineer’s toolkit. While it may appear simple on paper, when executed rigorously and integrated into modern development workflows, it provides deep insights into potential risks long before they reach the road. 

In an era of increasingly complex, software-driven vehicles, the challenge is not just to perform FMEA but to transform it from a compliance exercise into a proactive, intelligent safety strategy. 

Further Viewing