What is ISO 26262?
ISO 26262 is the international standard for functional safety in the automotive industry. It is based on IEC 61508, but is specifically tailored to the requirements of automotive E/E systems (Electrical/Electronic systems).
The standard describes how manufacturers can ensure the safety of vehicle electronics – from design through to production and maintenance.
🎯 Purpose of the standard
The aim of ISO 26262 is to:
- Identify and manage functional risks arising from systematic and random faults
- Implement a structured safety lifecycle
- Design components with demonstrable automotive safety integrity levels (ASILs)
- Meet safety expectations of the market, regulators and insurers
🧱 Structure of ISO 26262
| Part | Topic |
|---|---|
| Part 1 | Introduction and general concepts |
| Part 2 | Management of functional safety |
| Part 3–6 | Design, implementation, validation and production |
| Part 7 | Product use and maintenance |
| Part 8–9 | Supporting processes and analysis |
| Part 10 | Guidelines for interpretation |
| Part 11–12 | Additions for trucks, buses and motorcycles |
🧠 What is ASIL?
ASIL (Automotive Safety Integrity Level) is the defining safety level in ISO 26262. It determines how strictly a system must be designed and validated.
| ASIL | Meaning | Risk classification |
|---|---|---|
| ASIL A | Low safety-criticality | Limited injury |
| ASIL B | Moderate safety-criticality | Minor to moderate injuries |
| ASIL C | High | Serious injuries |
| ASIL D | Very high (highest level) | Life-threatening or fatal injuries |
| QM | Quality Managed | No functional safety measures required |
ASIL is determined via hazard analysis and risk assessment (HARA).
🧩 Linkage with other standards
| Standard | Relation to ISO 26262 |
|---|---|
| IEC 61508 | Parent standard for functional safety |
| ISO 13849-1 | Concerns machinery safety; different sector |
| ISO 21434 | For automotive cybersecurity (complementary to 26262) |
| ASPICE | For software processes, often used in parallel |
🔧 Application examples
| System | Possible ASIL |
|---|---|
| Airbag system | ASIL D |
| Adaptive cruise control | ASIL C–D |
| Electric power steering | ASIL C |
| Infotainment (no steering impact) | QM |
| Regenerative braking (EVs) | ASIL B–C |
✅ Best practices
- Implement a complete safety lifecycle (analysis → design → verification → validation)
- Use formal methods such as FMEA, FTA and HARA
- Document each ASIL level per component or subsystem
- Avoid ASIL Decomposition without careful control and documentation
- Use tools and components with ASIL certification wherever possible
📌 In summary
ISO 26262 is the standard for functional safety in automotive E/E systems. It helps manufacturers design safe vehicles through ASIL classification and a structured lifecycle.