Maintenance in the offshore wind sector is one of the primary cost drivers, largely due to the harsh marine environment and the logistical challenges of accessing turbines located far from shore. Operations are highly dependent on weather and sea conditions, often leading to long delays and complex management. The aim of the Thesis is to develop a methodology able to evaluate, from both a technical and economic perspective, the seasonal impact associated with corrective maintenance in the context of floating offshore wind turbines (FOWTs). Although it is not possible to precisely predict when a turbine will experience a failure, the proposed approach allows for a more reliable estimation of the associated intervention costs and expected downtime.  This analysis is based on metocean data, including significant wave height (Hs) and wind speed at 100 m from the ERA5 database.