In the hours after the Delta Air Lines computer outage last month, the airline resorted to an archaic form of passenger processing: Writing out boarding passes by hand.
Even after systems came back up, some were still slow, and gate agents in some cases had to manually enter codes from boarding passes.
The episode resulted in a huge black eye for Delta, with more than 2,000 flight cancellations over several days affecting people all over the world. The manual processes slowed check-in and boarding, delaying flights that did operate.
The Delta outage also sent a warning to any company that’s heavily dependent on technology for daily operations: Have a Plan B ready if things go haywire.