Nested reliability analysis of mooring lines for floating systems

► Reliability of moorings under uncertain sea states using a nested formulation. ► Response surfaces modeling mooring line tension parameters in terms of sea states. ► Partial safety factors calibration for ultimate limit state of mooring lines. ► Effect of neglecting randomness in dynamic tensions and some sea states parameters. ► Results for mooring lines for FPSOs at different water depths in Campeche Bay.