For Techies: Southwest Working Through GDS Ticketing Timing Issue

Southwest Airlines was kind enough to offer a lengthy response to a question posted by a reader of The Beat, and I thought it belonged here for the benefit of other readers, particularly those who know what the heck they're talking about! First, the reader question: [more]
"About a week ago we did an e-ticket via Sabre like we always do, and then got a confirmation e-mail like we always do. The difference was that this confirmation showed payment for the ticket, but not a ticket number. We called Southwest after noticing this, and they had to create a new passenger name record in order to issue the ticket. We’ve had situations this week where we get two confirmations for e-tickets issued via Sabre. The first has no ticket number, and then a few minutes later we get a confirmation with the ticket number."

And Southwest's response: "First, our apologies to your reader for the inconvenience. This sounds like a situation that we are currently trying to resolve. The situation that your reader describes involve BBR (Basic Booking Request) PNRs that we receive via direct communication with other distribution systems. They are not created by one of our front-end systems. The process to create these tickets is, thus, a two-step process. When we receive their initial request, we create a listing. At this point the PNR is not ticketed. The BBR process then communicates with the ticketing system to create the ticket and associate it with the PNR.

"There are two possible times at which the fulfillment can take place. The first time when the listing is made, and the second, after the ticket is associated with the PNR. There are potential timing issues that could cause a duplicate fulfillment. Let's see if I can explain those timing issues. Our fulfillment is driven from a feed that we get from SAAS [Southwest's reservation system]. Think of it like an email system. Our fulfillment receives these "emails" from SAAS which contains the PNR data. We use that data for the fulfillment. SAAS batches up the emails in one-minute intervals. This is to reduce the number of messages that are sent to us each day. If the listing and the ticketing occurred within the same minute, we would only see the ticketing. If they happened to not be in the same minute, we could potentially send multiple messages. It looks to us that this customer received the duplicate fulfillments due to timing issues.

"We are currently looking for reservations that are listings without a ticket. We put code into production [recently] that will prevent issuance of a fulfillment for unticketed reservations. Additionally, we are looking for other situations where we might potentially be sending duplicate fulfillments. We've made progress but are still working through it."