A well written post on the Lean CEO blog recently looked at the propensity of airlines to pad their schedules. The writer notes that this is a classic “inventory” solution to ineffective processes and a failure to apply lean thinking correctly. I agree. However, the writer misses the real purpose of the padded schedules.
The reason schedules were padded is because the published metric that airlines believe matters is on-time performance. They believe on-time performance drives preference. If they can improve on-time performance by padding the schedule that is much less expensive than actually solving the root cause problems.
While I do not work for an airline, I suspect they would also argue that most of the root cause problems of delays are outside their control; so padding the schedule is the right answer anyway.
While they continue to have these beliefs, and lose money, Southwest Airlines recognizes that planes on the ground do not make them any money, so they work to reduce ground time. And, they make money … consistently. That being said, they have added an average of about 10 minutes to their ground time planning as well.