Please using BPMN to ceate a case about Down Under Airlines.

Down Under Airlines (DUA) processes over 400 million tickets a year. The process of issuing the tickets is highly automated; a record of each ticket sold is stored in DUA's database. But when passengers turn in tickets, gate agents stuff the flight coupons into envelopes and ship them to DUA's Denver headquarters. Because of discrepancies between the original records housed in the ticket database and actual ticket use as reflected by the flight coupons, DUA, like other airlines, has to match every coupon against every ticket in the database in order to accurately account for passenger revenues. With the volume of tickets involved, manual matching is a daunting task. Image processing to the rescue!

DUA's new processing system, designed by one of the Big Four professional service firms, is designed as follows: When a ticket is sold to a passenger by a travel agent, by one of DUA's own 30,000 ticket agents, or online; the seller enters a record of the ticket into DUA's database, just as in the past. However, when flight coupons are received in Denver, they are now read by an image scanner that captures the images and stores them in an optical storage and retrieval library called Big File. The ticket number appearing on the flight coupon is also scanned by an optical character recognition (OCR) system. The ticket numbers (an index to the ticket images themselves) are stored in a relational database, which is used to track the location of each ticket image in Big File. Operators use a network of workstations to access ticket images. Special audit software matches each ticket image in Big File with ticket records in the mainframe database. If the image and record do not match (for instance, a three-leg ticket sold but only two legs used), the ticket number is included in the audit data. If the image and record do match, the ticket record is written to the passenger revenue data.