Offshore T&I operations of large and heavy structures are complex and high-risk activities, highly sensitive to uncertainties. This thesis presents the outcomes of a simulation-based model designed to analyze the impact of such uncertainties on offshore operation workflows.

By first identifying the key uncertainties that cause delays in offshore T&I projects through an in-depth literature review, the model was then tailored to capture them effectively. A hypothetical case study on transporting and installing prefabricated concrete caissons for the construction of an energy island is used to verify and demonstrate the capabilities of the model. Two strategies were assessed, one using a semi-submersible barge and one using the wet-tow method for transportation. Monte Carlo simulations were applied to capture the impact of the weather and operational uncertainties, as well as the probability of failure events. The results show that project performance is strongly influenced by factors such as execution timing, the simplicity of the operational step sequence and the operability limits.

The model is designed to be easily adaptable to a wide variety of offshore operations. Its structured outputs provide engineers and planners with a powerful tool to evaluate how critical parameters (e.g. weather conditions) affect the project performance and explore alternatives to determine the optimal one, in terms of time and resource availability.