Software Safety Training: Why Functional Safety Now Extends to Code

Functional safety used to be a hardware discipline. The safety function lived in a relay, a valve, a physical interlock, and safety engineering meant making that hardware reliable. That world is disappearing. Today the safety function increasingly lives in software: in the logic solver's program, in embedded firmware, in the code of a safety controller. Which means functional safety competence now has to extend to code, and software safety training has become a discipline of its own.

This guide explains why software is now a functional safety concern, what software safety training covers, what the standards require, and who needs it. It is written for software, systems, and controls engineers in Canada and the United States working on or moving toward safety-critical systems.

Software safety is the discipline of ensuring that software performing or supporting a safety function does so reliably. Unlike hardware, software does not fail randomly; it fails because of errors built in during development. That fundamental difference is why software safety needs its own methods and its own training.

Why Software Is Now a Functional Safety Concern

Two shifts brought software into the heart of functional safety. First, safety functions that were once hardwired are now implemented in programmable systems, so the correctness of the code directly determines whether the safety function works. Second, systems have grown complex enough that software is unavoidable, from safety PLCs in a plant to the electronic control units in a vehicle.

The critical insight is that software fails differently from hardware. A relay fails randomly, at a rate you can calculate and design around. Software does not wear out; it fails because a fault was introduced when it was written, and that fault was always there, waiting for the conditions that trigger it. You cannot manage that risk with redundancy the way you manage hardware failure. You manage it by controlling how the software is developed. That is what software safety, and software safety training, is about.

What Software Safety Training Covers

Software safety training teaches engineers to develop, verify, and manage software for safety-related systems in a way that controls the introduction of faults. Typical coverage includes the software safety lifecycle, requirements-driven development for safety functions, the design and coding practices that reduce systematic faults, verification and testing techniques suited to safety-critical software, and the management and documentation the standards require.

Crucially, it teaches the mindset difference: safety-critical software development is not ordinary software development done more carefully. It is a disciplined process with specific techniques, traceability requirements, and verification methods that ordinary development does not demand. Training is what instills that discipline.

 

Area	What Training Covers
Software safety lifecycle	The staged process from safety requirements through design, coding, verification, and validation.
Requirements-driven design	Deriving software safety requirements and tracing them through to verification.
Fault-avoiding practices	Design and coding techniques that reduce systematic faults in safety-related code.
Verification and testing	Methods suited to safety-critical software, beyond ordinary functional testing.
Management and documentation	The traceability and records the standards require for safety-related software.

IEC 61508 Part 3 and Software Safety

The requirements for safety-related software are set out in IEC 61508 part 3, the software part of the base functional safety standard. It defines the software safety lifecycle and the techniques appropriate for each Safety Integrity Level, with more rigorous methods required as the SIL rises. This is the reference point for software safety across industries, and the sector standards build on it.

Because software safety is grounded in IEC 61508, a functional safety certification that covers the base standard, such as the FS Eng (TUV Rheinland) program, includes the foundation that software safety competence rests on. Software safety training then goes deeper into the specific practices of developing and verifying safety-related code.

Software Safety in Automotive: ISO 26262

Nowhere is software safety more prominent than in automotive, where ISO 26262 governs the functional safety of road vehicle electrical and electronic systems. Modern vehicles run enormous amounts of safety-related software, from braking and steering control to advanced driver assistance, and ISO 26262 places heavy emphasis on the software development process. For engineers in the automotive sector across North America, software safety training aligned to ISO 26262 is often essential rather than optional.

ISO 26262, like IEC 61511, derives from IEC 61508, so the underlying software safety principles are shared. An engineer grounded in the base standard's approach to software carries that foundation into the automotive context.

Who Needs Software Safety Training

• Embedded and firmware engineers working on safety-related devices, controllers, or systems, whose code directly implements or supports safety functions.

• Controls engineers programming safety PLCs and logic solvers, where the safety function lives in the program they write.

• Automotive software engineers working under ISO 26262 on vehicle systems, where software safety is central to compliance.

• Medical and industrial device developers building products where software performs safety-related functions under IEC 61508 or a derived standard.

• Functional safety specialists who need to assess or manage software safety as part of a broader safety program, and must understand what good software safety practice looks like.

How Software Safety Fits the Certification Path

Software safety competence builds on functional safety fundamentals. The most coherent path is to establish grounding in the functional safety lifecycle and the base standard first, through a functional safety certification like the FS Eng (TUV Rheinland) program that covers IEC 61508, then deepen into software-specific practice through focused software safety training. That sequence means the software safety work rests on a solid understanding of the safety lifecycle it serves, rather than being learned in isolation.

Frequently Asked Questions

What is software safety training?

Software safety training teaches engineers to develop, verify, and manage software for safety-related systems in a way that controls the introduction of faults. It covers the software safety lifecycle, requirements-driven design, fault-avoiding practices, verification methods suited to safety-critical code, and the documentation the standards require. It reflects the fact that software fails from built-in errors, not random wear, and so needs its own discipline.

What standard governs software safety?

IEC 61508 part 3 sets out the requirements for safety-related software, defining the software safety lifecycle and the techniques appropriate for each Safety Integrity Level. Sector standards build on it, including ISO 26262 for automotive. Software safety training is typically grounded in IEC 61508 part 3.

Who needs software safety training?

Embedded and firmware engineers, controls engineers programming safety PLCs, automotive software engineers working under ISO 26262, medical and industrial device developers, and functional safety specialists who assess or manage software safety. Anyone whose work involves software that performs or supports a safety function benefits from it.

How does software safety relate to functional safety certification?

Software safety is grounded in IEC 61508, so a functional safety certification covering the base standard, such as the FS Eng (TUV Rheinland) program, provides the foundation software safety rests on. The coherent path is to establish functional safety fundamentals first, then deepen into software-specific practice.

Build Your Functional Safety Foundation

Arista Cyber delivers the FS Eng (TUV Rheinland) functional safety certification program, grounded in IEC 61508 including its software requirements, to engineers across Canada and the US. If you work on safety-related software and want a recognized foundation to build software safety competence on, we can help.

Enroll in the FS Eng (TUV Rheinland) Program