A boarding system and a computer-implemented method for boarding a plurality of passengers onto an aircraft, each passenger having an assigned seat on the aircraft. The boarding system 100 comprises a scheduling system 110 configured to control access of each of the plurality of passengers to a respective boarding path in accordance with a boarding schedule 112, each boarding path extending between a boarding gate and the assigned seat of the respective passenger; and a tracking system 120 comprising a plurality of monitoring devices, the tracking system 120 being configured to monitor behaviour of each of the plurality of passengers when moving along their respective boarding path. The scheduling system 110 is configured to modify the boarding schedule 112 in response to identification of a congestion point along a boarding path based on data received from the tracking system 120.