Human factors in electrical, electronic and programmable electronic safety-related systems

The thinking behind human factors guidance in support of IEC 61508 and 61511 is outlined. The structure and content of the guidance is described as being in two major parts. The first part comprises qualitative guidance on human factors within the safety lifecycle, human factors integration plans and the principal concerns of employing human factors processes techniques and knowledge for safety-related systems functions, design and assessment. The second part of the guidance describes the methods and considerations required to implement a multi-step human failure determination process that is directly relevant to safety integrity level determination in electrical, electronic and programmable electronic systems.