The concept of circularity is used as an alternative to linear flow materials in order to protect the environment from potential damage. To determine to what extent a sediment management project contributes to circularity practices, it is necessary to quantify how much of the dredged material is maintained within the system. Hence, defining boundaries for the system and circularity indicators for dredged material plays a vital role in measuring the circularity level of a certain project [1]. This study concentrates on defining circularity indicators for sediment management projects when a certain amount of material is diminished during the pre-processing stage. Besides, the perspectives of different stakeholders (e.g. port authorities, and dredging contractors) influence the selection of strategies for circular maintenance dredging [2].

Purpose: Maintenance dredging can often hinder port operations resulting in waiting times for seagoing vessels. The purpose of this paper is to investigate the dynamics between maintenance dredging activities and seagoing vessels, specifically focusing on how waiting times can be reduced. Then, the role of selecting different maintenance dredging strategies in reducing these waiting times is outlined. Methods: The study analyzes historical automatic identification system (AIS) data to identify the interaction between maintenance dredging and seagoing vessels and quantify the hindrance periods for the Mississippihaven case study in the Port of Rotterdam, the Netherlands. The trajectories of the vessels are analyzed in a simple case to show how the vessels interact and how the waiting times are quantified. The interactions are checked with the Port of Rotterdam for different port calls to ensure that maintenance dredging was the reason for these delays. Results: By analyzing the AIS data analysis of vessels in a given time window, the dredgers for maintenance work can be identified and their activities within or near the terminal can be determined. In addition, the waiting time of the seagoing vessel caused by the maintenance dredging is quantified at the terminal entrance. Conclusion: The study discusses how the maintenance dredging operations could be improved by adjusting the loading and sailing phases of maintenance dredging and provides some theoretical and managerial insights. Alternative port maintenance strategies to minimize the waiting time caused by the hindrance are also discussed.