本文章目前仅提供英文版本。
Functional Safety vs. SOTIF: What Is the Difference and Where Do They Overlap?
Safety has always been a top priority in the automotive industry, especially with the rise of autonomous driving technologies. Functional Safety (FuSa, ISO 26262) and Safety of the Intended Functionality (SOTIF, ISO/PAS 21448) play a critical role in ensuring safe mobility. But what is the difference between FuSa and SOTIF, and what characteristics do they overlap with? In this article, Elena Bley (Senior Manager Marketing & Webinars at MES) and Prof. Dr. Mirko Conrad (Managing Director at samoconsult GmbH) explore these concepts to help deepen your understanding of automotive safety.
Understanding ISO 26262 and SOTIF: Key Concepts Overview
What Is Functional Safety (FuSa, ISO 26262)?
Functional Safety (FuSa) is defined by ISO 26262 standard in the automotive industry, as the absence of unreasonable risk due to hazards caused by malfunctioning behavior of E/E systems.
What Is Safety of the Intended Functionality (SOTIF, ISO/PAS 21448)?
Defined by ISO 21448 standard published in 2022, Safety of the Intended Functionality (SOTIF) emphasizes the absence of unreasonable risk due to hazards resulting from functional insufficiencies of the intended functionality or its implementation. SOTIF is especially important for automated driving systems (ADS).
Differences, Overlaps, and How They Complement Each Other
Both FuSa and SOTIF aim to ensure safety, but they focus on different aspects. Understanding how FuSa and SOTIF complement and differ from each other is important for deepening your understanding of these concepts. In the figure below, we illustrate the key differences and overlaps between FuSa and SOTIF.
FuSa mainly addresses faults in E/E systems, while SOTIF mentions functional insufficiencies, functional insufficiencies of AI-based algorithms, and incorrect/inadequate Human-Machine Interface (HMI) design.
Although FuSa and SOTIF address different aspects of safety, they complement each other in achieving safety assurance, such as:
- Reasonably foreseeable misuse
- Impact from active infrastructure
- Impact from Vehicle-to-Vehicle (V2V) communication
- Impact from external systems
- Impact from vehicle surroundings
Debate exists, the relationship between Functional Safety and SOTIF, including their overlaps and distinctions, is still an evolving topic. As part of the third edition of the ISO 26262 standard (ISO 26262:2027), a dedicated working group is exploring how to incorporate elements of safe nominal performance into the Functional Safety framework.
Conclusion
Functional Safety and SOTIF are both irreplaceable in ensuring automotive safety, as they cover distinct topics while complementing each other in many aspects. Understanding the differences and connections between these two concepts is essential for fully grasping their scope and applying them correctly in real-world automotive developments. This article illustrates it clearly and explains their relationships. As the standards continue to evolve, so too will the connections between FuSa and SOTIF. Therefore, it is crucial to keep our knowledge up to date to stay ahead.
More Offers from tudoor academy
To extend further, we at tudoor academy (a collaboration between samoconsult GmbH and Model Engineering Solutions GmbH) offer you plenty of resources to meet your needs to learn more about FuSa and SOTIF.
Training: Safety of the Intended Functionality (SOTIF) for Automotive Professionals
In this training class, we compare and contrast functional safety and safety of the intended functionality, review the conceptual SOTIF framework and fundamental terminology, and provide an overview of activities and methods to achieve SOTIF.
Article: Differences and Synergies Between Functional Safety, SOTIF, and Cybersecurity
In this article, we thoroughly discussed the differences and synergies of these three concepts. If you would like to extend this topic further, here is the chance!
Webinar: Beyond Functional Safety: SOTIF
In this webinar, you learn about the conceptual framework of SOTIF and to get an overview of the SOTIF life cycle as per ISO 21448.
Webinar: Safety Analyses According to ISO 26262 at a Glance
In this webinar, we introduce the main types of safety analyses (FTA, FMEDA, FMEA) and explain their role in the safety-related development process as per ISO 26262.
