What is ISO 26262? — Everything About Automotive Functional Safety

What is ISO 26262?

ISO 26262 is the international standard for functional safety of automotive electrical and electronic systems. In simple terms, it's the methodology for ensuring software errors don't lead to human injury.

Vehicles contain many systems — brakes, steering, airbags, ADAS — where malfunction can cause harm. ISO 26262 provides a framework for systematically ensuring safety throughout the entire development lifecycle.

First published in 2011, the 2nd Edition released in 2018 is currently in use, with expanded coverage including semiconductors and motorcycles.

ASIL — Safety Levels Based on Risk

The core concept of ISO 26262 is ASIL (Automotive Safety Integrity Level), classifying risk into four levels from A to D.

• ASIL A — Lowest risk. Example: interior lighting control
• ASIL B — Medium risk. Example: rear camera
• ASIL C — High risk. Example: ABS, airbags
• ASIL D — Highest risk. Example: electric power steering (EPS), automatic emergency braking (AEB)

Higher ASIL levels require stricter development methods and verification. ASIL is determined by three factors: Severity, Exposure, and Controllability.

V-Model and ISO 26262

ISO 26262 follows a V-Model development process. The left side represents development (requirements → design → implementation), and the right side represents verification (unit test → integration test → system test). Each development stage has a corresponding verification stage, with ASIL-appropriate methods and artifacts required at every level.

ISO 26262 vs. ASPICE

Both standards apply to automotive software development but serve different purposes. ISO 26262 focuses on safety — preventing software errors from causing accidents. ASPICE focuses on process quality — ensuring development processes are systematic and repeatable. In practice, both are applied together.

The Most Challenging Part in Practice

The most effort-intensive aspect of ISO 26262 compliance is verification. Higher ASIL levels demand higher test coverage, mandatory traceability, and comprehensive documentation. This is driving adoption of automation tools for test case generation, coverage analysis, and traceability matrix construction.

PopcornSAR's PARVIS was built to address exactly this challenge. In real projects, PARVIS-Verify has reached 86.4% test coverage, and PARVIS-Coder brought MISRA-C compliance from 40% to 94%. The tool handles both ASPICE and ISO 26262 artifact generation in a single workflow.

Considering automation for your compliance process? Check out the PARVIS product page or reach out for a conversation.