Read ticket
details
Validate
ticket
Refer to airline
staff
Allocate seat
Ask for confirmation
Print
boarding
pass
Allow seat
change
Ticket
Database
Seating Plan
Ticket-details
Invalid-ticket-details
Ticket-details
Ticket-details and seat allocation
Ticket-details and seat allocation
Boarding-pass
Ticket-details and seat allocation
Ticket-details
Checkin control
Ticket-entered