Functional Safety

Functional Safety is a key aspect of overall system safety that focuses on reducing the risk of physical injury or harm caused by failures in electrical and electronic (E/E) systems. It ensures that these systems operate correctly in response to their inputs and, in the event of a malfunction, automatically trigger protective or corrective actions to prevent hazardous situations or bring the system to a safe state.

The goal is to eliminate unreasonable risk and safeguard people by anticipating and managing potentially dangerous failures.

While the core principles of Functional Safety are universal, its implementation is governed by industry-specific standards, especially in fields where system failures can lead to severe consequences.

For example, the automotive industry follows ISO 26262, which is derived from the more general IEC 61508 standard used in industrial automation.

Other industries have their own standards:

• Cybersecurity in Automotive, ISO/SAE 21434

• General Functional Safety, IEC 61508

• Aerospace Industry, DO-178C & DO-330

• Industrial Safety, IEC 61511 & ISO 13849

• Medical Device Industry, ISO 62304

• Railway and Transit Systems, IEC 61508 & EN 50128

• AI safety in automotive ISO/PAS 8800

These standards ensure that Functional Safety is appropriately tailored to the unique risks and requirements of each sector.

Vehicles are becoming increasingly sophisticated, with more critical functions controlled by interconnected E/E systems. Consider features like Anti-lock Braking Systems (ABS), Electronic Stability Control (ESC), airbags, or Advanced driver-assistance systems (ADAS) functions. A failure in any of these could lead to hazardous situations, potentially resulting in injury or loss of life.

Functional Safety provides the framework to systematically identify potential hazards arising from system malfunctions, assess the associated risks, and implement measures to reduce those risks to an acceptable level. Without a rigorous approach to Functional Safety, the increasing complexity of vehicles would lead to unacceptable levels of risk.

The development of complex systems relies heavily on software tools which are instrumental in creating, modifying, and verifying the safety-critical systems. However, if a tool malfunctions, it can directly or indirectly compromise the safety of the final product.

This is why standards like ISO 26262 place strong emphasis on the qualification of tools and the integrity of the development processes. Tools must first be classified and, depending on their classification, a tool qualification process may be required.