Abstract The connections between structural reliability and system reliability are reviewed, emphasizing their intimate dependence. The problem of model validation is then outlined; the importance of data in this respect is analyzed. The role of structural reliability in the set-up of regulations and standards is shown to be the statistical analysis of the ‘safety margin’ provided by component design. Furthermore the importance is stressed of implementing a continuous feedback between analysis and operational data on individual structures in order to improve and update prior estimates and models.