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Abstract In the recent offshore engineering industry, larger, heavier and more complex structural systems are adopted and require more stringent design requirements. This is due to the growing demand of a bigger operational capacity and harsh marine environments. Therefore, the need of reliable and accurate analysis simulation is important in this situation especially when the non-availability of the new transportation vessel forced the project to use the existing and available vessel assets. Comprehensive and accurate analyses can provide better results in terms of loadout and transportation analyses of heavy module structures. This current approach involves an overall analysis of the structure configurations, which comprises the topside and the transportation vessel along with its hydrodynamic simulations as opposed to conventional approaches, which only consider analyses related to the topsides with strict boundary conditions on the topsides-vessel intersection. The implementation of the integrated analysis would facilitate better design optimization and accuracy in comparison to conventional analyses. The model used for the integrated analysis includes simulation of the topside and the transportation vessel, while considering the hydrodynamic forces due to the environmental factors, the direction of the wave, and water pressure. The simulation employs a panel model to produce the possible water pressures, which are then applied to the shell element i.e. a thin structure represented by 2D surface with a defined thickness in finite element software, model representing the transportation vessel. This methodology has been implemented in the actual project case for loadout and transportation of heavy Jacket structure for the deep water with the weight of 25,000 MT which has been installed successfully. The analysis and model were developed based on DNV-ST-N001 and DNV-CG-0127 for the hull and jacket model into finite element simulations. The stress checks are performed based on API-RP-2A recommendations. To ensure the accuracy of the hydrodynamic responses interaction to the transportation vessel, Response Amplitude Operators (RAOs) which are important parameters for major rotational responses of the transportation vessel such as roll and pitch are checked based on its global hydrodynamic analysis results. This calibration ensures that the responses used in the integrated analysis are realistic and accurate. Furthermore, reactions are checked to confirm that the floating body behaves correctly, with reaction forces ideally summing to zero or negligible under steady-state conditions. Implementing this approach facilitated design optimization, enabling to use the existing vessel asset with the weight reduction of the structure/sea fastening and improved efficiency during loadout and transportation, ultimately contributing to safer and more cost-effective operations. Integrated hydrodynamic analysis provides a more accurate assessment of offshore structure behavior during loadout and transportation operations, crucial for heavy structures where payload, vessel, and weight management are critical.