Because it was planned in pre-production. When you decide to shoot a film, the first thing that happens is the script gets 'broken down' into a database with every single production element involved in every scene. I mean everything - if a character has a handbag over her shoulder and later pulls a tube of lipstick out of it, the lipstick and the handbag get their own pages in the breakdown, they're linked with each other, someone is assigned the responsibility to procure, pay, maintain custody of it, and so on...and on and on and on. Your typical feature film has maybe 100 scenes, and even a no-budget film will probably generate an average of 10 things per scene. On a big-budget film as described in the article, it could be 10x that.

This process takes 1-2 weeks minimum, and forms the basis of the budget and the schedule. Then you add in constraints for this and that (Famous Actress is only available for one week, so all her scenes will have be shot between these two dates; we'll have X hours and minutes of daylight available on any given date; union rules mean that if we shoot longer than 16 hours in a single day we start paying everyone their full day rate for each additional hour (yes that's really true, but it hardly ever happens). So at the end of this you have a realistic estimate of time and cost for the production itself. You end up with a document called the 'Day Out of Days' which itemizes every single scene and possibly every single camera setup in the film, and what particular things/people will be required for them.

Then you set about raising the money, and when you have all that in place you go into pre-rpoduction, securing locations, building props, getting signatures on contracts and so on. Things falling through at this stage can cause big delays (on reason that I'm reading HN today rather than shooting) but most contracts go into effect on the first day of principal photography so the financial costs are limited.

During production, everyone on the cast and crew gets a copy of the schedule for the following day the evening before, telling them where they'll be working, what they'll be doing, what stuff has to be there etc. etc. This usually undergoes substantial revisions at the end of every shooting day depending on whether production is ahead of or behind schedule, what random things have changed and so on. You work for 12+ hours a day, and everything you do is scheduled down to 15 minute increments. Then you drink a beer and either go home or sit in a production meeting for 1-2 hours and work out the potential problems for the following day.

Think of it as a cross between military logistics of setting up a forward operating base (minus the risk of being shot at) and planning a wedding. It's great, it's really rewarding, but like these events it is a ton of hard work and you probably go to bed mentally and physically exhausted every night. On your days off you probably hang out with the same people you are already working with and eat more food, watch a couple of movies, hold more production meetings, and then get up and start working again.