What is ISO 26262?

Introduction to ISO 26262 Standard

ISO 26262 is the functional safety standard for automotive electronic and electrical (E/E) systems. It defines a structured, V-model-based development lifecycle to assess and mitigate risks that may arise from malfunctioning system.

The standard introduces Automotive Safety Integrity Levels (ASILs) to classify risks, ensuring safety measures are proportional to potential hazards. It impacts OEMs, Tier-1s, and semiconductor suppliers who develop safety-critical systems like ECUs, ADAS, and battery management.

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What is the Purpose and Scope of ISO 26262?

As automotive systems become more complex and increasingly rely on software, sensors, and electronics, the potential for safety-critical failures has grown, making standards like ISO 26262 essential.

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Key Components of ISO 26262

• Early Hazard Identification and Safety Goals

  ISO 26262 emphasizes on identifying hazards early in the concept phase through HARA. The process of Hazard Analysis and Risk Assessment (HARA) is the first step in ISO 26262 compliance journey. It is followed by setting specific safety goals to manage those hazards.

• Functional Safety Lifecycle

  The standard’s framework encompasses multiple phases:

  • Concept Phase: Hazard and risk analysis, assigning ASIL levels.
  • System and Software Development Phases: Safety requirements and design.
  • Hardware Development Phase: Ensuring hardware safety, like in ECUs.
  • Integration and Verification: Testing and validation to ensure safety targets are met.

• ASIL: Automotive Safety Integrity Level

  ISO 26262 uses ASIL levels to categorize safety-critical functions, from ASIL A (least stringent) to ASIL D (most stringent). These levels are assigned based on factors like severity, exposure, and controllability.

  
  • Severity: The potential impact of a failure.
  • Controllability: How easily drivers or systems can control or mitigate a failure.
  • Exposure: The likelihood of exposure to the hazardous scenario.

  ASIL determination sets the tone for rest of the safety-lifecycle. ISO 26262 standards have clear guidance on testing methods, tool qualification etc. based on ASIL value.

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What Role Does ISO 26262 Standard Play in the Automotive Industry?

ISO 26262 provides a structured approach to risk assessment and mitigation throughout the automotive product lifecycle, from concept to production and decommissioning. Its primary role is to establish a framework that ensures automotive systems are designed and tested to uphold safety throughout their lifecycle.

This includes making sure that components like ECUs, sensors, and software are designed to detect and handle faults safely, minimizing hazards.

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How ISO 26262 Standard Aligns with Other Automotive Standards?

ISO 26262 aligns with other automotive standards like MISRA, ASPICE, AUTOSAR, and AEC-Q100 to create a comprehensive framework for functional safety, quality, and reliability in vehicle systems.

While each of these standards addresses different aspects of automotive development, they complement ISO 26262 in various capacities. Together, these standards add specific guidelines with respect to software quality, process improvement, modular architecture, and hardware reliability.

Here’s a detailed look at how ISO 26262 aligns with these standards.

1. MISRA (Motor Industry Software Reliability Association)

   MISRA provides coding guidelines for developing safe, reliable, and maintainable software in the automotive industry, primarily targeting the C and C++ programming languages.

   Alignment with ISO 26262:

   • ISO 26262 requires software development processes to be safe and reliable, especially for high ASIL-rated functions.
   • MISRA guidelines support ISO 26262 by reducing potential software errors, improving code quality, and minimizing risks associated with software failures.
   • Together, they ensure that software for critical functions, like Brake ECU or Airbag Control Units, is coded in a way that minimizes vulnerabilities and ensures predictability

2. ASPICE (Automotive SPICE)

   ASPICE is a process assessment model designed to improve software and system development processes in the automotive industry. It provides a framework for evaluating and improving the maturity and quality of these processes.

   

   Alignment with ISO 26262:

   • ISO 26262 mandates rigorous safety processes for developing and validating automotive systems. ASPICE’s process assessments align with ISO 26262 requirements, ensuring that development processes meet safety and quality standards.
   • ASPICE and ISO 26262 together emphasize process maturity in safety-critical systems, such as EPS and AEB systems, ensuring that each development stage adheres to best practices.
   • Implementing ASPICE supports ISO 26262 compliance by providing a structured approach to managing and improving development processes, which is essential for meeting functional safety requirements.

3. AUTOSAR (Automotive Open System Architecture)

   AUTOSAR provides a standardized software architecture for automotive electronic control units (ECUs). It enables the reuse of software components, improving compatibility and integration across different platforms.

   Alignment with ISO 26262:

   • ISO 26262 and AUTOSAR together ensure that reusable software components meet safety standards, allowing these components to be integrated reliably in different ECUs.
   • AUTOSAR’s modular approach supports ISO 26262 by allowing components to be independently tested and verified for safety compliance. For instance, an AUTOSAR-compliant EPS ECU module can be developed according to ISO 26262, ensuring it meets ASIL requirements.
   • AUTOSAR’s communication protocols and safety measures align with ISO 26262 standard guidelines on safety validation, ensuring that modules perform safely and predictably.

4. AEC-Q100 (Automotive Electronics Council Qualification)

   AEC-Q100 is a qualification standard for the stress testing of integrated circuits (ICs) used in automotive applications. It ensures that ICs meet the rigorous environmental and reliability standards required for automotive applications.

   Alignment with ISO 26262:

   • ISO 26262 requires that hardware components meet reliability and durability standards, especially for ASIL-rated systems.
   • AEC-Q100 testing ensures that ICs used in safety-critical systems, like Brake ECUs and Airbag Control Units, perform reliably under harsh conditions, complementing ISO 26262’s requirements for hardware robustness.
   • Together, AEC-Q100 and ISO 26262 provide a comprehensive approach to verifying that hardware components can withstand extreme temperatures, vibrations, and electrical stresses, which is crucial for vehicle safety.

5. IATF 16949 (International Automotive Task Force)

   IATF 16949 is a global quality management standard for the automotive industry. It focuses on continuous improvement, defect prevention, and reducing variation and waste in the automotive supply chain.

   Alignment with ISO 26262:

   • ISO 26262 complements IATF 16949 by focusing on functional safety in system design and manufacturing processes.
   • IATF 16949’s quality management principles support ISO 26262 by ensuring that suppliers and manufacturers follow consistent quality practices for safety-critical parts, like those used in ADAS or EPS systems.
   • Together, these standards ensure that automotive systems are produced to high-quality standards and incorporate robust functional safety requirements.

6. ISO 21434 (Road Vehicles – Cybersecurity Engineering)

   ISO 21434 is a standard focused on cybersecurity management for automotive systems. It ensures that cybersecurity threats are managed effectively throughout the vehicle’s lifecycle.

   Alignment with ISO 26262:

   • ISO 26262 focuses on functional safety, while ISO 21434 addresses automotive cybersecurity. Together, they create a holistic approach to risk management in automotive systems.
   • For systems like connected braking or steering systems, ISO 21434 ensures that cybersecurity risks don’t compromise functional safety. ISO 26262 and ISO 21434 together protect these systems from both safety-related and cyber-related failures.

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Steps in ISO 26262 Compliance

Achieving compliance requires a series of well-defined steps that, while rigorous, can be streamlined into an organized process. Let’s walk through the key steps.

1. Initiate Safety Lifecycle and Conduct Hazard Analysis & Risk Assessment (HARA)- The initial step in the ISO 26262 safety lifecycle involves identifying potential hazards that the E/E system might introduce and assessing their associated risks. The process begins with defining the safety lifecycle and performing Hazard Analysis and Risk Assessment (HARA). This involves identifying potential hazards associated with the system's functionality and evaluating risks in terms of severity, exposure, and controllability. Each hazard is assigned an Automotive Safety Integrity Level (ASIL) rating, ranging from ASIL A (low) to ASIL D (high), which determines the safety measures required to address the hazard.
2. Define Functional Safety Requirements- Based on the ASIL ratings established in the HARA process, functional safety requirements are formulated. These requirements specify what the system must do to reduce or eliminate the risk of hazardous events. For instance, a system may need to maintain control in adverse conditions or respond within a specific timeframe to prevent potential failures. Functional requirements set the foundation for designing a system that aligns with the safety needs of the application.
3. Translate Functional Requirements into Technical Safety Requirements- Technical safety requirements are derived from the functional requirements and address how the system architecture and components should be designed to achieve functional safety. This step outlines specific technical responses, such as redundancy, diagnostics, or specific safety mechanisms, that ensure the system can detect, manage, and mitigate risks associated with potential failures.
4. Develop Hardware and Software to Meet Safety Requirements- Hardware and software are developed according to the defined safety requirements, following ISO 26262-compliant development processes. Hardware must incorporate fail-safe elements and withstand stress factors relevant to automotive conditions. Software development includes implementing error detection, fault management, and backup protocols. This stage also requires extensive unit testing and code reviews to ensure each element meets its safety requirements.
5. Verification and Validation- Verification and validation (V&V) ensure that the entire system, including hardware and software, meets safety requirements. Testing techniques include simulations, hardware-in-the-loop (HIL) testing, and real-world testing to validate that the system performs reliably under various conditions and can effectively handle safety-critical scenarios. Validation confirms the system’s alignment with initial safety objectives and functional requirements.
6. Conduct Functional Safety Assessment and Approve for Production- Before release, an independent functional safety assessment verifies that the system meets ISO 26262 requirements. This assessment may be internal or external, depending on the ASIL level. Reviewers examine documentation, test results, and compliance reports to ensure the system's development has followed the required safety processes. Once all criteria are met, the system receives approval for production, marking its readiness for the automotive market.

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What are the Benefits of ISO 26262 Standard?

Automotive electronics now account for up to 40% of a vehicle's total cost. It is evident that safety cannot be an afterthought. It must be embedded right from the start of the development lifecycle.

ISO 26262 standard aligns to the V-model of automotive solutions development (software, hardware and system design). Hence, it easy to adopt by all automotive stakeholders.

Here’s a quick overview of the benefits of ISO 26262 standard:

• Standardized Safety Framework: ISO 26262 establishes a universal framework that automotive companies can follow, ensuring consistent safety practices across the industry. It thus makes it easier for stakeholders to collaborate on safety-critical projects.
• End-to-End Lifecycle Safety Management: The standard provides a structured approach for managing safety at every stage of a component's lifecycle—from concept through development, production, and even decommissioning—ensuring comprehensive safety oversight.
• Supplier and OEM Alignment: ISO 26262 creates a unified set of safety requirements, enabling better alignment between OEMs and suppliers. This minimizes production risks and ensures that all safety-critical parts meet stringent standards.
• Concurrent Hardware and Software Development: Recognizing the integration of hardware and software in modern automotive systems, ISO 26262 offers guidelines for their concurrent development and testing, ensuring a holistic approach to system safety.
• Holistic System Testing and Validation: The standard mandates testing methods based on the Automotive Safety Integrity Level (ASIL), therefore providing a consistent approach to safety that aligns testing rigor with risk level.
• Reduction of Safety-Related Failures: ISO 26262 helps prevent system failures by embedding safety measures early in development, significantly reducing the risk of defects that could lead to recalls or in-field failures.
• Support for Regulatory Compliance: With safety regulations becoming stricter globally, ISO 26262 provides a reliable framework for manufacturers to meet regulatory standards.
• Enhanced Consumer Trust and Market Confidence: As a globally recognized standard, ISO 26262 enhances consumer confidence in the safety of automotive electronics, supporting OEMs and suppliers in building trustworthy brands.
• Framework for Functional Safety Innovation: ISO 26262 enables manufacturers to innovate within a structured safety framework, supporting the development of advanced systems like ADAS and autonomous features while maintaining safety integrity.

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What are the Challenges in ISO 26262 Compliance?

Implementing the ISO 26262 standard introduces additional layers of effort into automotive development, yet it is essential for ensuring functional safety.

Given that ISO 26262 is both comprehensive and applies to every phase of the development cycle, it presents several challenges:

1. Complexity of Functional Safety Requirements: ISO 26262 has rigorous safety requirements, including hazard analysis, risk assessment, and safety integrity levels (ASILs) determination. Identifying and correctly applying ASILs can be complex and varies widely depending on the systems involved.
2. Integration Across the Supply Chain: Compliance often requires collaboration between OEMs, Tier 1 suppliers, and other parts suppliers. Aligning standards, practices, and documentation across various companies in the supply chain can be challenging due to differences in maturity, expertise, and expectations.
3. Resource-Intensive Documentation and Process Management: ISO 26262 demands extensive documentation to demonstrate compliance, covering every phase from concept to production. This can be time-consuming and requires dedicated resources and robust process management.
4. Training and Expertise: Implementing ISO 26262 often requires specific technical knowledge in functional safety, system engineering, and automotive standards. Training staff and hiring experts can be challenging, especially for smaller companies or those new to the automotive sector.
5. Adaptation for Legacy Systems: Many automotive systems may not have been designed with functional safety in mind. Retrofitting ISO 26262 standards to existing systems can be technically challenging and costly, as it might require significant redesigns or testing.
6. Balancing Safety and Innovation: ISO 26262 compliance can sometimes slow down the development of innovative technologies, as it requires additional validation, verification, and rigorous testing. Balancing safety requirements with the rapid pace of technology, especially in areas like autonomous driving, can be difficult.
7. Tool Qualification: All tools used for the development and testing of safety-critical systems must themselves be validated to ensure they do not introduce errors. Achieving compliance with these standards for third-party tools is challenging, especially if they were not initially developed with functional safety in mind.
8. High Development and Testing Costs: Implementing ISO 26262 involves comprehensive testing, including failure mode analysis and fault injection testing. These steps are essential for safety but can significantly increase both time and financial investment.

How Embitel Helps Automotive OEMs and Tier 1s in ISO 26262 Compliance?

Embitel Technologies has been one of the early adopters of ISO 26262 standards. Having delivered a range of ISO 26262 compliant projects to Tier-1s, we have experience in the entire spectrum of ISO 26262 standard. Check out our ASIL D Brake ECU and Electronic Power Steering ECU projects to know more.