Absolutely you can predict sickies or unscheduled leave. The science is presently called
Predictive analytics - Wikipedia. But in 1970 Walmart was running data cubes, and stuff now called AI. Airlines are operational - many moving pieces, and my other favorite OP or
Operations research - Wikipedia. For fares, some of the dumber airlines trust the revenue maximization engine, only they fail to use all available inputs. Worse, they don't audit or cost mistakes, or listen to old hands screaming 'lead time'. The really rich use PA all the time - especially share speculation and futures.
Management should be numerically literate, but they are not, and chose to ignore bad news - not enough doctors, not enough teachers. The new mantra is other peoples problems, not on my written performance criteria. Or can we not do this - See Origin Energy and automated hardship - seeing if they can outdo Robodebt. Or QF and lost baggage - kick that one to the curb.
Covid is difficult, but the UK has a world class predictive model, as does Denmark. Maybe you overheard a colleague about maxxing out their sick leave to get more overtime - work the system and all that. Recruitment shops care about beating hearts, not work ethic, and are never punished for placing job hoppers. Say 'Mechanical issues' when you really mean not enough bums on seats, or one flight attendant called in sick meant the whole flight was cancelled.
Plus 35 days, fares are about normal, even knowing oil avgas is dearer. We all know airports are an understaffed zoo, with throw a dart automated check in games. Being needed badly - helps your job security. I need to second source plane pax numbers, to work out if seat reduction numbers, drove that revenue engine crazy. We observed 30-40K one way fares during covid, and I have a hunch that the revenue engines are sill defective, never fixed.
If that is complicated, HR's job is to make sure employees never see these numbers, else the might try on for a pay rise. If it was me, I would be issusing 'bonus payments' for those employees making a critical difference.