The seaport is a complex facility, the work of which is affected by many external factors. Its efficiency is provided by the competent scheduling of the operations performed. The previously developed automated system allowing to generate the optimal cargo handling schedule in the sea cargo port and considering the dynamic effect of external factors on its efficient operation requires the controlling the execution of planned operations and the strict compliance with the schedule. In this paper, we review the multi-agent approach providing the work performance control according to the schedule. In case of unforeseen changes in external factors rendering impossible the existing plan execution (vessel delay, equipment breakdown), agents track the source of the problem and inform the dispatcher about the need for adjusting the operations' schedule.