ISO 26262-4:2018

Overview

ISO 26262-4:2018 - Product development at the system level is a part of the ISO 26262 functional safety framework for road vehicles. It specifies requirements and work products for system-level activities when developing safety-related systems that include electrical and/or electronic (E/E) components installed in series-production road vehicles (excluding mopeds and certain special-vehicle unique E/E systems). The standard provides a framework to integrate functional safety into company-specific development lifecycles and addresses both technical product requirements and process-level obligations for demonstrating safety.

Key topics and technical requirements

• Technical safety concept and specification of technical safety requirements - define system-level safety goals and translate them into concrete technical safety requirements.
• System architectural design - establish an architecture that satisfies safety requirements, including allocation of safety functions across hardware and software.
• Safety analyses and management of systematic failures - perform analyses to identify hazards and design measures to avoid or mitigate systematic faults.
• Measures for random hardware failures - define architecture-level measures to control random hardware failures during operation.
• Allocation to hardware and software & Hardware-Software Interface (HSI) - allocate requirements to HW and SW elements and specify HSI contents to ensure correct integration.
• Integration and testing (item, system, vehicle level) - plan and execute integration strategies and verification tests to confirm safety requirements are met.
• Safety validation - validate that the integrated system meets the original safety goals in the intended operational context.
• Lifecycle tailoring and legacy systems - guidance on tailoring the safety lifecycle for alterations to production systems and integration of existing systems not originally developed under ISO 26262.
• Scope limits - hazards like electric shock, fire or toxicity are excluded unless directly caused by malfunctioning E/E systems.

Practical applications and users

ISO 26262-4 is used by:

• Automotive OEMs and Tier-1/2 suppliers to define and verify system-level safety requirements.
• Functional safety engineers and system architects for developing safety concepts and system architectures.
• Integration and test teams responsible for HW/SW integration, system testing and vehicle-level validation.
• Project managers and safety assessors for planning safety lifecycle activities and evidence collection.

Typical applications include ADAS modules, powertrain control systems, braking or steering E/E systems, and any safety-related E/E system requiring ASIL-based development and validation.

Related standards

ISO 26262-4 is part of the ISO 26262 series (functional safety for road vehicles) and complements other parts covering management, hardware and software development requirements (e.g., parts addressing hardware and software development, production, and supporting processes). Annex A provides workflow guidance and Annex B gives example HSI contents.

Keywords: ISO 26262-4:2018, functional safety, system level, automotive safety, E/E systems, technical safety concept, system integration, safety validation, ASIL.