A Guide to Functional Safety and Safety Certification

A Guide to Functional Safety and Safety Certification

Do you want to build safety systems? Do you want to safety-certify an embedded product with complex software? Safety certification demonstrates compliance with a safety standard such as IEC 61508, the basic functional safety standard for electrical, electronic and programmable electronic safety-related systems, and industry-specific standards such as IEC 62304 for medical devices, ISO 26262 for vehicles, IEC 60880 for nuclear power plants, EN 50128/50129 for rail systems and ISO 25119 for agricultural and forestry equipment.

At BlackBerry QNX, safety is at the heart of everything we do. We have safety certified our products and helped many of our clients to safety certify their systems. In this guide, you’ll learn why it’s important to shift your primary focus from certification to building safe systems. Building safe systems is more about promoting a safety culture in your organization and following best-practice processes, so safety is considered at every step in the software development lifecycle.

What Is Functional Safety?

Functional safety is the absence of unreasonable risk due to hazards caused by malfunctioning behavior. Functional safety requires the safe management of software errors, operator errors, hardware failures and environmental changes. A key aspect of functional safety is that it depends on the continuous operation of a safety-related system—an active system that detects and responds such as a fire suppression system and not a passive safety system such as fire-resistant door.

A functional safety system is a secondary system designed to prevent unintended harm to people, property and the environment. In addition to hardware and software, a functional safety system also may include protective equipment worn by the operator, system maintenance, and guidance for the safe use of the product such as a safety manual and operator training.

Systems are demonstrated to be functionally safe when they have been assessed and issued certification as compliant with a safety standard by an accredited third-party certifier such as TÜV Rheinland. Sometimes involving a third-party certifier is optional. For some industry-specific standards, such as ISO 26262, companies can self-assess their own compliance.

Almost all safety standards impose requirements on processes that, if followed systematically throughout the software development lifecycle, can increase the level of safety in systems.

Read More to learn about safety terminology that will help you better understand safety certification, functional safety standards, building safe systems and making safety claims. 

Get a free copy of the foundational book on functional safety, Embedded Software Development for Safety-Critical Systems, by Chris Hobbs.