Validation

Validation is the process of confirming that a system is safe and fit for use in its intended operational environment. It demonstrates that the developed item achieves its defined safety goals when operated under real-world conditions, including foreseeable misuse, faults, and failures.

In automotive systems governed by ISO 26262, validation ensures that safety-related functions perform correctly at the system or vehicle level when hardware and software are fully integrated.

Validation and verification are complementary but distinct activities within the functional safety lifecycle.

• Verification: Confirms that development outputs meet specified requirements and design specifications.

• Validation: Confirms that the final system fulfills its intended safety purpose and meets safety goals in real operating conditions.

In simple terms:

1. Verification asks whether the system was built correctly.

2. Validation asks whether the correct system was built for its intended use.

In ISO 26262, validation is typically performed in the later stages of the development lifecycle, after major verification activities have been completed.

Validation is primarily carried out at the system or vehicle level to confirm that all integrated components such as hardware and software work together to achieve the specified safety functions and safety goals.

Validation is crucial because it provides final evidence that a system is safe to operate in its intended environment.

Even when individual components are verified, system-level hazards can arise from integration effects, environmental stress, or fault conditions. Validation identifies these risks and ensures that safety mechanisms perform as expected under realistic operating scenarios.

Without robust validation, there is no definitive proof that a system meets its safety goals, which is critical in standards such as:

• Automotive – ISO 26262

• Aerospace – DO-178C

• Rail – EN 50128

• Industrial control – IEC 61508

ISO 26262 defines validation as a structured, safety-critical process that includes:

• Clearly defined validation scope

• Specified operating and environmental conditions

• Objective acceptance criteria linked to safety goals

• Realistic system-level test scenarios

• Documented validation evidence and results