The automobiles we use to commute from one place to another have become intelligent machines. In the last couple of decades, we have seen many electronic functions, including software in a car that can help the driver make informed decisions and, at the same time, perform required tasks by itself, thus enabling an enhanced user experience and safety. However, the presence of such complex safety-critical functions can also increase the risk of failure. This is where risk assessment under ISO 26262 is implemented during the concept phase of the development process to ensure functional safety in automobiles.

Before moving on to the approaches in ISO 26262, let’s first understand why it is important for automotive companies and what benefits it provides.

ISO 26262 serves as a standard for ensuring vehicle safety. It provides structured guidelines that carmakers follow to maximize safety for their customers and minimize danger.

Automotive Risk Assessment: Helps to Minimise Risk Level

One big benefit of sticking to ISO 26262 is that it makes cars safer. As part of ISO 26262 functional safety, automotive risk assessment helps identify, analyse, and mitigate potential hazards, giving car companies a structured approach to safety risks. By following these rules, car companies can reduce the potential risks associated with their vehicles, thereby improving vehicle reliability and safety through better risk management.

It’s also a way for carmakers to show they follow the rules. Governments and regulators have strict safety standards, and following ISO 26262 helps car companies meet those requirements and support compliance.

Functional safety helps to avoid business losses.

Another advantage of ISO 26262 is that it helps automotive firms manage risks through a structured process. They must assess all potential car problems and prevent them, enabling informed decisions and reducing recalls and warranty costs by catching issues early. That means fewer surprises down the road.

Helps in reducing time-consuming rework

ISO 26262 gives carmakers a roadmap for building cars. It details, step by step, how to design, test, and build vehicles through development, ensuring safety and reliability, though compliance can be resource-intensive and complex.

By following ISO 26262, car companies ensure their vehicles are less likely to break down or experience problems. Strong functional safety processes keep safety work consistent from concept to production. This leads to happier customers and fewer headaches for carmakers.

And because ISO 26262 is recognised worldwide, it helps automotive companies sell their vehicles in different countries. Documentation and continuous monitoring are essential for compliance and accountability. People everywhere want safe cars, and ISO 26262 shows that a car meets those standards, no matter where it’s sold.

Overall, sticking to ISO 26262 helps these companies build safer, more reliable vehicles, keeping everyone on the road safer and happier.

Analysing the situation and risk assessment

Hazard identification is a critical step in the automotive risk assessment process, so the situation and the operating modes in which the vehicle malfunctions must be considered when analysing the failure. These situations, operating modes, and the potential risks they pose must be recorded and analysed effectively. Risk analysis evaluates the likelihood and severity of identified hazards. Possible hazards can be identified using various software tools or through field trials in a controlled environment. This supports analysis and risk assessment based on consequences, with a comprehensive review that considers both functional safety and human factors. Cybersecurity risks should also be considered when evaluating vehicle malfunctions.

Classifying the Hazards in Hazard Analysis

After identifying potential hazards, classify them by three factors: severity, controllability, and probability of exposure, as defined by ISO 26262. Hazard analysis and risk evaluation in ISO 26262 compare these hazards against predefined safety thresholds. In the automotive industry, this classification occurs within a structured, cyclical risk assessment process, not as a one-time activity.

Severity

Each hazard can have a different severity, since not all failures lead to fatal problems. The key question is how much damage it could cause to passengers or the driver. Under ISO 26262, we assign severity levels to safety-related and electrical or electronic systems.

Probability of Exposure

Just as there are different severity levels, there are also classes of exposure probability. In modern vehicles, proactive risk assessments address safety risks because exposure depends on how and where the vehicle is used. Exposure probability varies with operational situations and can be assigned to relevant classes based on hazard estimates.

Controllability

Another factor to determine is whether, in a hazardous event, the typical driver can control the vehicle, as controllability indicates if malfunctioning behaviour could cause unpreventable system failures. Controllability must be determined and classified into different levels.

Determining ASIL

ASIL (Automotive Safety Integrity Level) is a risk classification system defined by ISO 26262, with four levels—A, B, C, and D, where D is highest. Levels are based on severity, controllability, and probability of exposure. The assigned ASIL then guides risk treatment by defining measures to mitigate identified risks.

Safety-critical systems such as anti-lock brakes, power steering, and airbags require ASIL-D due to their highest failure risks. In contrast, rear lamps require ASIL-A, headlamps and brake lights require ASIL-B, and cruise control systems fall under ASIL-C.

Forming Safety Goals

Safety goals are top-level security requirements. Each evaluated hazard can have a safety goal. ISO 26262, an international standard, was first published on November 11, 2011; its second edition, published in December 2018, expanded the scope to all road vehicles. Safety goals are functional objectives across the safety lifecycle, not part of the technological solution. A single hazard may require multiple safety goals.

Incorporate additional factors to fulfill your functional safety requirements. Understanding and effectively applying these approaches will help you meet functional safety requirements according to standards, improving the overall driving experience and safety. eInfochips leverages experience in automotive smart systems such as ADAS, Telematics, Infotainment, Clusters, and Multimedia Systems. eInfochips is well versed in automotive standards like ISO 26262 and has delivered systems certified according to various regulatory standards. To learn more about our automotive expertise, contact us.

Frequently Asked Questions

1. How does ISO 26262 risk assessment impact the design process for new vehicle features?

ISO 26262 integrates risk assessment early in the concept phase, influencing how new electronic and software features are designed. By identifying potential hazards and required safety measures upfront, engineers can build safety into the design rather than retrofitting it later.

2. What practical challenges do automotive companies face in achieving ISO 26262 compliance?

Compliance with ISO 26262 can be resource-intensive and complex, often requiring thorough documentation, multidisciplinary collaboration, and continuous monitoring throughout the development lifecycle. These challenges may affect timelines and costs for new vehicle programs.

3. How do severity, controllability, and probability of exposure interact to determine the Automotive Safety Integrity Level (ASIL)?

The ASIL is determined by evaluating how likely a hazard is to occur (probability of exposure), how severe the outcome could be, and whether a typical driver can control the situation. The combination of these factors ensures that the most critical risks are subject to the highest safety requirements.