Table 2.

Passenger recovery algorithm

Steps	Location	Actions
1a	Passenger recovery \ Cale PAX recovery	Clean range containing previous alternative flight searches.
1b	Passenger recovery \ Cale PAX recovery	Set all German passengers traveling domestically to “leave”.
1c	Passenger recovery \ Cale PAX recovery	Randomly assign “leave” to German passengers traveling internationally in 70%, 50%, or 30% of the cases based on the selection made, all remaining will be assigned “stay”.
Start loop 1
2a	Passenger recovery \ All	Set current scenario (1–4) in the dashboard, refresh all worksheets, and filter ranges in descending order in alternative flights
Start loop 2
3a	Passenger recovery \ Cale PAX recovery and Passenger recovery \ alternative flights	For passenger X, search (match function) for the next possible available flight (based on origin, destination, operating airline, and departure date) available without considering seat capacity restriction nor the passengers’ origin but only on the first run cycle. Destination airport must however remain the same.
3b	Passenger recovery \ Cale PAX recovery and Passenger recovery \ alternative flights	For the same passenger X, search (match function) for the next possible available flight with the restriction of the same airline or alliance or none of the listed restrictions based on the selected recovery option at the beginning. Searching for origin, destination, operating airline/alliance/none, and departure date. Destination airport must however remain the same.
3c	Passenger recovery \ alternative flights and Passenger recovery \ seat capacity	Check (match function) the seat capacity from the previously found flight. If seats are available, continue next and write the record found in the corresponding passenger record in the “calculated PAX recovery” worksheet. If not, go back to the beginning (3b) and search for another flight five minutes later.
End loop 2
2b	Passenger recovery \ alternative flights and Passenger recovery \ Cale PAX recovery	If the passenger is German and no seat is found, search (match function) for the possible available train keeping the destination airport the same. If a train is found, write the record in the corresponding passenger record in the “calculated PAX recovery” worksheet. If no train was found, write “no available flight nor train found” in the corresponding passenger record in the “calculated PAX recovery” worksheet.
2c	Passenger recovery \ alternative flights and Passenger recovery \ Cale PAX recovery	If the passenger is not German, write “no flight alternative found overall” in the corresponding passenger record in the “calculated PAX recovery” worksheet.
End loop 1

Source: Own Elaboration