There is an urgent need to reduce emissions from maritime transportation to meet environmental targets set by international organizations and governments. To reduce emissions from maritime transportation, technical, market-based, and operational measures can be used. In this thesis, the focus is on operational measures, and in particular Just-in-Time arrival in the port call process. Just-in-Time arrival in the context of port calls refers to maintaining an optimal vessel sailing speed to arrive to the port when the availability of berth and other services are ensured. In earlier studies, the estimated fuel and emission savings potential of Just-in-Time arrival, is promising. Despite the promising potential of Just-in-Time, its implementation remains limited, with few real-world examples. The purpose of this thesis is to explore how to implement Just-in-Time arrival by studying coordination in the port call process.  

Two research questions were formulated to address the purpose. The first aims to capture the potential benefits of implementing Just-in-Time arrival in port calls. The second aims to address what is required to implement Just-in-Time arrival. This thesis is based on two studies in the Swedish context. First, a quantitative study, in which Automatic Identification System data in combination with port call statistics and vessel-specific data were used to estimate the fuel and emission savings potential of Just-in-Time arrival. Second, a qualitative single case-study exploring the coordination mechanisms necessary for implementing Just-in-Time arrival in port calls was conducted.   

The studies show that fuel and emission savings potential of Just-in-Time in previous studies is overestimated due to the assumptions used. Though, the implementation of Just-in-Time has potential to improve port call actors’ resource planning and utilization and increase the competitiveness of ports. This is because Just-in-Time arrival has the potential to aid actors in reaching mandatory emission reduction targets. To implement Just-in-Time arrival, it is necessary to coordinate the plans of actors. The required mechanisms to coordinate planning are pre-booking berth allocation policy and port community systems. The pre-booking policy implies booking time-slots for berths, facilitated by using the port community system. The port community system and the pre-booking policy enable effective coordination of the planning processes of individual actors, enabling Just-in-Time arrival in port calls.