I will use an analogy:
There is a race starting in 2 weeks time (custom built vehicles only).
There are two teams.
Team 1) The "do it right team"
Team 2) The "do it quick and do it cheap team"
Neither team has a car yet.
The Winner of the race secures finances to fund their team for another year. The loser, well, they don't.
Team 1 start deciding if they want a shiny F1 car or a Muscular Nascar and deliberate over how padded the seat should be and which direction the window winder will rotate. Oh, and what colour decals. They spend 1.5 weeks documenting what they want. They then determine it will take 14 weeks to build using a sub-contractor and that testing of the car will take another 4 weeks with some modifications made after. Total cost $4,000,000
Meanwhile Team 2 has decided to use a plank of wood with a few cheap caster wheels and some pedals. Designed in 1 day and built in 1 week. Total cost $120
Race day comes !
Team 1 say their car is "going" to be great. Fast, shiny and cool. They are disqualified for not having a car.
Team 2 show up with a pedal car to the bemusement of judges.
The Race :
Although problematic as the wheels fell of twice, but because of the simple design, fixing mid race was a doddle. Team 2 win, although not in style. But they win and secure funding.
Moral of the story.
It doesn't matter how supportable or amazing your system is if it does not deliver when needed.
Just because you have an IT process does not mean you must doggedly follow it (ITIL). Do what is needed for your organisation. Hell, build them a sh*tty pedal car if that's what is needed to stay in business.