Adequate structural safety is ensured by proper design, fabrication and operational criteria as well as inspection and monitoring and possible repair during fabrication and the service life of 20 to 40 years. Since an inspection and repair strategy implies a need for robustness, progressive failure or accidental collapse limit state design criteria are of special importance. While the design and inspection criteria in modern codes have been calibrated on a generic basis, particular features of individual structures imply that it is necessary to update the initial inspection plan based on operational experiences. In this connection fatigue cracks are of special concern.The first updating of reliability could be based on the information obtained during fabrication and in the inspection of the as-fabricated structure. A particular issue is to document a safe extension of the service life of existing platforms in view of fatigue cracks. In this paper recent efforts to establish rational, reliability-based procedures for life cycle assessment of fixed offshore platforms is outlined. To ensure confidence in the methodology used it is shown how the reliability methods is tied to the semi-probabilistic approach that current codes are based on; as well how the reliability approaches relate to operational experiences.