Integration according to IEC 61508

Integration according to IEC 61508 is the process of providing an engineered safety-related solution, usually comprising 3rd party subsystems to the all embracing risk graded requirements, of the International Safety Standard IEC 61508. The systems integrator may include all or some of the subsystems that comprise an overall solution but this invariably includes the central logic solver. The electrical, electronic or programmable electronic central logic solver may be relay, solid state or software based respectively. The primary objective of the standard is founded on risk assessment and risk reduction. The level of risk reduction should be based primarily on applying ALARP and not solely by meeting the minimum target integrity requirements set by the standard. The principle of ALARP is based on reducing the level of risk to as low as reasonably practicable, within the tolerability region, until the cost incurred becomes disproportionate to the benefit gained. The introduction of IEC 61508 must represent one of the most significant advances towards a unified approach to achieving functional safety. The consequences that may arise due to an inappropriate safety installation resulting in an incident could be immense. Therefore the responsibility of integrating safety-related systems to IEC 61508 should not be taken lightly. It is ultimately the responsibility of the Overall Project Safety Management, to ensure that Functional Safety has been achieved by the correct application of IEC 61508.