New/Seasonal route logistics


When an airline commences a new route or a seasonal route, how do they initially establish the equipment and personnel needed?

For instance take the seasonal Icelandair flight between BIKF-KSFB


The ground handling at SFB is outsourced to a ground handling company (TBI plc in this case). Icelandair simply has to agree to a price with them to service the aircraft. All that Icelandair has to do is send signage to the airport (or send specifications if the airport will have it built for them) and provide the ground handling company with logins and computers/software for their computer reservations system.