Travelers can use the American Airlines app, sign up with their AAdvantage account, or simply provide contact information during check-in. When the plane lands, you get a notification via text, email, phone call, or push notification if your baggage hasn't arrived as planned.
There are three alerts you might receive. "Early Baggage Arrival" means your baggage arrived before you, and you should head to baggage services instead of the Great Conveyor Belt of Waiting. "Late Baggage Arrival (BSO)" means you need to go to the baggage service office for more information.
The third alert, "Late Baggage Arrival (MBO)," means you need a mobile baggage order. The process of having your baggage delivered to where you're staying can be time-consuming. But the alerts aim to reduce time spent tracking bags by instantly alerting you to the situation and allowing you to fill out forms right in the app.