A computing unit allocates boarding paths, available for boarding a transport unit, in particular an aircraft, to passengers of the transport unit. An associated method allocates boarding paths, available for boarding the transport unit to passengers of the transport unit. A computer program carries out the method, and a directing system directs passengers of the transport unit along boarding paths available for boarding the transport unit. The computing unit is configured to form two or more changeable seat groups from a plurality of seats provided in the transport unit and to allocate the boarding paths, available for boarding the transport unit, to the two or more seat groups formed.