Frequent Flyer Mileage System is an extenral application which has the award mileage information about the customer.You need to show that your application iteracts with this in order to get mileage account information of customers.
Just so it is clear, the requirements clearly state that seat selection needs to happen even before the itinerary can be saved. I guess since seat selection and payment can happen at different times, seats will not be reserved until the payment occurs.
And inside of my fortune cookie was this tiny ad:
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