#1 Manufacturing Glossary - SYMESTIC

ISO 26262

Written by Symestic | Aug 25, 2025 8:14:35 AM

Definition

ISO 26262 is the international standard for functional safety in the automotive industry that defines systematic methods to avoid unreasonable risks from malfunctions of electrical and electronic systems in vehicles. The standard covers the entire product lifecycle from concept phase through development and production to operation and decommissioning.

Automotive Safety Integrity Levels (ASIL)

ISO 26262 classifies safety risks into four ASIL levels (A to D) based on Severity, Exposure probability, and Controllability. ASIL D represents the highest risk and requires the strictest development processes.

Hazard Analysis and Risk Assessment (HARA) systematizes hazard identification and risk classification for all vehicle functions. Safety Goals derive directly from HARA results and define safety requirements.

Functional Safety Concept specifies necessary safety measures, while Technical Safety Concept describes their technical implementation.

Core Requirements and Processes

Safety Lifecycle: Structured V-model process with defined phases, deliverables, and verification activities. Each phase requires specific work products and quality management.

Functional Safety Management: Overall responsibility for safety activities, competence management, and configuration management. Safety Manager coordinates all safety-related processes.

Hardware-Software Interface (HSI): Systematic integration of safety-critical hardware and software elements with defined interfaces and failure modes.

Automotive Industry Benefits

  • Legal Security: Systematic fulfillment of legal liability requirements and product responsibility
  • Risk Minimization: Proactive identification and treatment of safety-critical malfunctions
  • Market Acceptance: Increased confidence in autonomous and semi-autonomous vehicle systems
  • Cost Optimization: Structured development reduces late design changes and recalls
  • Competitive Advantage: Proven safety competence as differentiation feature

Applications

Autonomous Driving: ADAS systems and autonomous driving functions require ASIL D classification for critical path planning algorithms. Sensor fusion and redundancy concepts ensure fail-safe behavior.

Electric Mobility: Battery Management Systems, high-voltage control units, and charging systems follow ISO 26262 processes. Thermal runaway prevention and emergency shutdown functions are safety-critical.

Connected Car: Over-the-air updates and cybersecurity measures must meet functional safety requirements. Security-safety interface prevents safety compromise through cyber attacks.

Chassis and Powertrain: Electronic Stability Control, Anti-Lock Braking, and Steering Systems implement ASIL-compliant development processes with extensive verification and validation.

Development Process and Tools

Model-based development with safety analysis tools supports early hazard identification. FMEA, FTA, and FUSA-TARA analyses are standardized methods.

Requirements traceability connects safety goals with technical safety requirements and their implementation. Bidirectional traceability is auditably documented.

Tool qualification according to ISO 26262-8 classifies development tools according to their safety relevance. Tool Confidence Levels determine necessary qualification measures.

Hardware and Software Development

Hardware: Systematic capability analysis, hardware metrics (SPFM, LFM), and architectural metrics validate safety architectures. Dependent failure analysis identifies common cause failures.

Software: Software safety requirements, architectural design, and unit testing follow ASIL-specific criteria. Coding guidelines and static analysis tools support defect prevention.

Integration: Hardware-software integration with safety analysis and systematic testing strategy. Production integration considers manufacturing variability.

Verification and Validation

Systematic testing strategy covers all ASIL requirements. Test case generation is based on safety requirements and failure mode analysis.

Hardware-in-the-loop (HIL) and vehicle-in-the-loop (VIL) testing validate safety functions under realistic conditions. Field testing collects statistical evidence for safety argumentation.

Management and Governance

Functional safety assessment by independent assessors validates process conformity. Safety case documents all safety evidence systematically.

Configuration management and change control ensure safety relevance is considered in changes. Impact analysis evaluates safety implications.

Integration with Other Standards

ISO 21448 (SOTIF - Safety of the Intended Functionality) complements ISO 26262 for AI-based systems. Cybersecurity standards like ISO/SAE 21434 address security-safety interface.

ASPICE process model harmonizes with ISO 26262 development processes. Automotive SPICE and ISO 26262 assessments can be conducted jointly.

Future Developments

Machine learning and AI integration require extended safety methodologies. ISO 26262 Edition 3 addresses autonomous systems and ML-specific challenges.

Edge computing and 5G communication create new safety-relevant architectures with distributed safety functions.

ISO 26262 evolves into the central safety standard for future mobility that safely enables autonomous driving, electrification, and connectivity.