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Functional / System Safety 

Many high profile accidents in recent years have involved interactions of complex systems, often including the human and/or software elements of those systems.  The IEC defines Functional Safety as ‘part of the overall safety that depends on a system or equipment operating correctly in response to its inputs.’  Failure, malfunction or poor performance of the system can lead to safety problems which depend on that function.  This means that safety problems may not be directly identifiable without deep investigation of possible malfunctions.


This shows the importance of treating System Safety as an engineering discipline: not just assessing risks for a particular system design, but influencing that design for good safety characteristics.  This can include consideration of appropriate technologies, use of redundancy for key functions and the interaction of people operating or using the system (Human Factors Integration).


A rigorous process of Safety assurance is essential in order to ensure that the potential for equipment to enter use with unacceptable safety characteristics is minimised.  The SAS team is committed to ensuring your project provides an appropriate level of assurance.  SAS has considerable experience in all aspects of Functional Safety, including: 

  • Safety Functional Analysis 

  • System Safety Modelling (e.g. Fault Tree Analysis, Event Tree Analysis, Bow-Tie Analysis) 

  • Software Safety Assessment 

  • Human Factors Assessment (e.g. Task Analysis, Human Error Analysis)

  • Safety Integrity Level (SIL) requirements setting and assessment using relevant Standards (e.g. BS EN61508)



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