Automotive 26262 Functional Safety Assessment | Safety Analysis


About ISO 26262

ISO 26262 is a standard that automotive professionals worldwide use to ensure the safety of electronic systems in vehicles. It summarizes possible electronic malfunctions in vehicles, describes ways to monitor these malfunctions and proposes ways to mitigate them. It provides these suggestions for every phase of the manufacturing process, from concept to decommissioning.


What Are The Benefits of ISO 26262?


Adopting ISO 26262 helps ensure that the safety of car components is considered from the beginning of the development process. It provides a comprehensive framework for managing safety throughout the entire lifecycle of an automotive component, from initial risk assessment to final decommissioning. By following ISO 26262, automotive manufacturers can ensure that their suppliers are meeting safety standards, preventing costly issues from arising during the production process.


The standard takes into account the trend of increasing integration of hardware and software in automotive electronic systems. It provides detailed guidelines for concurrent development and testing of hardware and software, recognizing that they must be tested together to achieve optimal safety. This ensures that all aspects of the system are considered and tested together, promoting a more comprehensive and thorough approach to functional safety.


Safety practices are becoming more regulated as industries adopt a standardized set of practices for designing and testing products. ISO 26262 addresses the needs for an automotive-specific international standard that focuses on safety critical components. ISO 26262 is a derivative of IEC 61508, the generic functional safety standard for electrical and electronic (E/E) systems. This paper covers key components of ISO 26262, and qualification of hardware and software. Additionally, this paper covers ISO 26262 test processes and qualifying tools for ISO 26262 compliance.


ISO 26262 is a risk-based safety standard that's derived from IEC 61508. It applies to electric and/or electronic systems in production vehicles. This includes driver assistance, propulsion, and vehicle dynamics control systems.

The functional safety standard covers all of the functional safety aspects of the entire development process:

- Requirements specification

- Design

- Implementation

- Integration

- Verification

- Validation

- Configuration


Any tools used in automotive development need to be qualified. Part 8 of ISO 26262 provides guidance for tool qualification.

Achieving ISO 26262 for RAM Commander/Safety Commander software tools covered:

Qualification plan.

Software tool documentation.

Software tool classification analysis.

Software tool qualification report.



The HARA process is used to identify and analyze potential hazards associated with the automotive system. Hazards can include events or conditions that could cause harm to people or damage to the environment. The HARA process involves identifying the root causes of these hazards and determining their severity and likelihood of occurrence. This analysis considers both systematic and random failures and their potential effects on the system.


Once potential hazards are identified, the FMEDA process is used to assess the safety of the system by analyzing the failure modes, their effects, and their diagnostic coverage. The FMEDA process involves analyzing the behavior of each component in the system and assessing the probability of each component failing. This analysis is used to determine the safety goals and requirements for each component.


The combination of HARA and FMEDA provides a comprehensive safety assessment of the automotive system. It helps to identify potential hazards, assess the risks associated with them, and develop safety goals and requirements to mitigate those risks. This process also ensures that the diagnostic coverage of each component is sufficient to detect and diagnose potential failures in the system.


The HARA FMEDA process is a critical component of ISO 26262 and is used to ensure the functional safety of road vehicles. It helps to identify potential hazards, develop safety goals and requirements, and verify that the safety measures are effectively implemented to mitigate risks.




After the HARA (Hazard Analysis and Risk Assessment) process is completed, the next step in the functional safety assessment of automotive systems according to the ISO 26262
standard is the FMEDA (Failure Modes Effects and Diagnostic Analysis) process.


The FMEDA process is a quantitative analysis that provides a prediction of the failure rate, diagnostic coverage, and failure modes of the components in the system. It involves collecting data about each component in the system, including failure rates, failure modes, and diagnostic coverage.



The FMEDA process includes the following steps:


Component selection: All components of the system must be identified and classified based on their function and potential impact on safety.


Component failure mode analysis: The failure modes for each component must be identified and classified. The severity of each failure mode is assessed based on the potential impact on safety.


Failure rate analysis: The probability of each failure mode occurring must be determined using historical data, field experience, or statistical models.


Diagnostic coverage analysis: The level of diagnostic coverage for each component must be determined, including any diagnostic measures that have been implemented to detect or prevent failures.


Calculation of metrics: Using the data collected in the previous steps, metrics such as failure rate, failure modes, and diagnostic coverage are calculated for each component.


Analysis and interpretation of results: The results of the FMEDA process are analyzed and interpreted to determine the overall safety of the system. If any components are found to have an unacceptable level of risk, additional safety measures must be implemented. The FMEDA process provides a quantitative analysis of the potential failures and their effects on the system. This information is used to determine the overall safety of the system and to identify any necessary improvements or modifications that need to be made to ensure functional safety according to the ISO 26262 standard.







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