Risk-based inspection framework for outer hull of floating units based on the integration of inspection programs

This study proposes a risk-based framework for planning underwater inspections of the outer hull of floating units. The framework aims to rationalize planning and move beyond the fixed schedules prescribed by classification societies, allowing inspection intervals to be defined according to actual risk conditions. Its main innovation lies in the integration of data from other mandatory inspection programs, such as thickness measurements, with qualitative evidence from Underwater Inspection in Lieu of Drydocking. This integration enhances the capacity to quantify degradation by establishing risk-informed inspection intervals supported by measurable indicators. The proposed framework is structured into three main processes: Organize data, responsible for collecting inspection and engineering information; Assess current condition, which estimates the probability and consequence of failure using structural reliability and risk analysis; and Plan underwater inspection, which defines inspection intervals according to the remaining useful life and acceptable risk levels. A case study conducted on a 20-year-old FPSO demonstrated the framework's applicability and its potential to adjust inspection intervals, either extending or shortening them, based on quantitative evidence. The results highlight that the framework supports decision-making that is data-driven, traceable, and committed to safety, ensuring that inspection planning remains both technically justified and aligned with regulatory requirements.