For various reason bookings may be added to a queue automatically to ensure that particular actions are carried out by users of the system.

A typical example of this is when an airline makes a schedule change to a flight or a range of flights.

Every booking which has been made on a flight where a schedule change has occurred is sent to the relevant sales office queue where the booking was made. It is then the responsibility of that sales office to regularly check the queue and in turn advise their customers of the schedule change (it is also possible for an automatic email to be sent to customers to advise the change)