This study focuses on the analysis of the dwell time of vessels at the Port of Sines jurisdiction ar-ea, between 2010 and 2023, as an indicator of operational efficiency. A total of 157,515 records of vessel movements were analysed, using statistical modelling in Python. The overall average dwell time calculated for these 13 years was 0.55 days, for a medium number of port calls per year of 2199. This result highlights the operational efficiency of the Port of Sines, although the variability between the different terminals remains significant. The Multipurpose terminal regis-tered the longest dwell time (1.08 days), especially due to the diversity of cargo handled. In con-trast, the Container terminal had an average dwell time of 0.38 days. The anchoring frequency has emerged as critical for optimization. The implementation of the Just-in-Time principles is proposed as a strategy to reduce anchorage times, enhance coordination and collaboration within the operational chain, and mitigate greenhouse gas (GHG) emissions. Notwithstanding the effi-ciency attained by the Port of Sines, this study suggests that further enhancement of its opera-tional efficiency is feasible and desirable. This would contribute to the sustainability agenda and reinforce the port's position in the global trade landscape.