IEC 61508 Viewpoint on System Safety in the Transport Sector

Part 1 – An Overview of IEC 61508

Abstract

IEC publication 61508 “Functional safety of electrical/ electronic/programmable electronic safety related systems” is probably the most widely-accepted, international generic standard on functional safety.  Although its roots can be traced to process industries, the intention behind the Standard has always been to provide a solid, comprehensive basis for adaptation to a wide range of industry sectors.  Nevertheless previous published research into safety engineering practices in the transport sector has shown that, in some areas, those practices fail to recognise even some of the most basic principles of IEC 61508 and, as a consequence, focussed far more on the reliability of safety-related systems and not enough on their potential risk-reduction properties. A series of papers, including this paper, will explore how IEC 61508 could be applied directly to the transport sector, with substantially beneficial results; no attempt is made to compare those results with actual practices in the applications covered – that is left to readers with a specific interest in those applications