From the airbus CEO however I have no idea what it means.

Airbus CEO Guillaume Faury said “ “We are focused on the A320neo ramp-up and improving the industrial flow while managing the higher level of complexity on the A321 ACF in particular. Our nine-month delivery numbers and the updated delivery outlook for the year reflect the underlying actions to secure a more efficient delivery flow in the next years as we progress to rate 63 per month for the A320 Family in 2021.”

Another statement from a airline CEO,
Disappointed, as you've heard me say previously, with the performance of Airbus,” Walsh told investors during Q2 2019 earnings call on August 2, 2019. “Very poor delivery from Hamburg on the A321. It's not just for us, as you know. I'm sure by now you've heard every airline that is excited about taking the 321LR expect - express huge disappointment about the delays that they're encountering.”

“We need Airbus to improve their performance, and they need to get working on that very quickly because, quite honestly, the delays that we're seeing are just completely unacceptable, and it is impacting on the growth plans that we have.