What are the requirements of the standards IEC 61508 / IEC 61511 in relation to the SIS life-cycle? 10th April 2018 A What are the requirements of the standards IEC 61508 / IEC 61511 in relation to the SIS life-cycle? IEC61508/IEC61511 requires that FSAs should be undertaken on a periodic basis as well as key stages in the SIS lifecycle by independent, competent person(s), department(s) or organisations.
