IEC 61508 – Functional Safety of Electrical/Electronic/Programmable Electronic Safety-related Systems

IEC 61508 addresses functional safety for electric, electronic and programmable systems used in energy, transportation or industrial applications. It covers system design, hardware design and software design as well as the core processes that underpin each of these processes, including configuration management, quality assurance and functional safety.


IEC 61508 is composed of seven parts:

  • IEC 61508-1, General requirements
  • IEC 61508-2, Requirements for E/E/PE safety-related systems
  • IEC 61508-3, Software requirements
  • IEC 61508-4, Definitions and abbreviations
  • IEC 61508-5, Examples and methods for the determination of safety integrity levels
  • IEC 61508-6, Guidelines on the application of IEC 61508-2 and IEC 61508-3
  • IEC 61508-7, Overview of techniques and measures

Verocel’s tools and services support compliance with IEC 61508. Our company plans have been approved to meet IEC 61508 objectives by the TÜV SÜD Certification Body.

Verocel follows a standard set of company plans and standards for all development and verification processes, supported by project-specific documentation. In 2011, TÜV SÜD conducted its first audit of our plans, conducted site visits, and granted approval of these company plans for IEC 61508 compliance. Since then, Verocel has submitted periodic updates to TÜV SÜD to maintain this approval of our processes for IEC 61508.

Functional Safety

Functional safety addresses the overall safety of electrical, electronic or programmable electronic systems, identifying potential risks and providing corrective actions or mitigations for those risks.  Functional safety is addressed at Verocel via the following:

  • A company standard Functional Safety Management Plan to identify the Functional Safety Management (FSM) organizational responsibilities and integral processes used during the software development and verification life cycle to achieve the required functional safety objectives.
  • Support of the FSM organization to verify the functional safety compliance for a project through standard audits and reviews.
  • FSM records to document the functional safety assessment planning activities and results.
  • Generation of project documentation to support IEC 61508 certification efforts, including Safety Manual, Safety Plan, Vulnerability Analysis.
  • Audit support with our customers and certification authorities.

Thanks to the TUV SUD approval of our certification approach, Verocel is well-positioned to take on an IEC 61508 certification project with ease and proven success.

Key changes to IEC 61508-3 (software):

The latest revision of IEC 61508 (edition 2.0) was published in 2010, placing an emphasis on correctness and completeness regarding software verification and thus making the use of qualified services and tools even more important. The key changes related to software in IEC 61508 edition 2.0 include:


  • Introduction of the idea of desirable Properties (such as completeness, correctness and predictability) for the output of each lifecycle phase.
  • Provision of extended requirement for the selection and justification of software development tools.
  • Allowing software elements which were not originally developed with safety in mind to be re-used in safety related applications by the provision of suitable evidence including evidence of successful use in other applications.
  • Revision to the set of technique and measures in Annexes A and B, to remove obsolete or little-used techniques and introduce current methods.

Verocel’s tools are qualified to support IEC 61508 requirements. Qualification documentation is provided in the form of a tool qualification plan and tool qualification data. Each tool supports a critical part of software assurance to IEC 61508 SIL 2, 3 or 4.

Verocel’s services support IEC 61508 qualification for application software or COTS software. Our qualification services use TÜV-approved IEC 61508 processes and can ensure you meet your cost and schedule requirements for your industrial, transportation or energy project.