that's not a reasonable goal. this idb situation happened because 4 crew showed up last minute in order to preserve the outbound flight at the downline station, not because the airline egregiously oversold and didn't figure it out until everyone was seated. whether ua knew about this hours out and could have avoided it or whether this happened with zero notice (my guess is an obvious communication breakdown between ux and the ua gate agents). also the w+b issues on smaller planes which can cause idb. idbs are a fact of life (at a minuscule amount of total trips taken) unfortunately.
We may be saying the same thing here: I suggest that zero-IDB can be a goal, and an airline can get incredibly close by using technology better. I realize they cannot fully get to zero.
I don't believe IDB will be banned outright as some suggest. I continue to remain in favor of overselling, whether to paying passengers or with confirmed crew movements as part of the passenger load. Even the best technology and intentions of an airline can't prevent a broken seat, a weight issue, or some other reason that an IDB *could* happen.
The only regulatory fix is a simple one: make the IDB cash compensation meaningful, require each airline to fully publish their entire IDB algorithm, and provide some simple consumer protections on the instruments offered as VDB. Don't need to overhaul the system or change airline revenue management models. Just a measured action to provide some basic consumer protections that don't exist today.