What circumstances might lead an entire organization (or business unit) with a federal IT governance design to change to a centralized IT governance design?

What circumstances might lead an entire organization (or business unit) with a federal IT governance design to change to a centralized IT governance design?

What circumstances might lead an entire organization (or business unit) with a federal IT governance design to change to a centralized IT governance design?
What circumstances might lead an entire organization (or business unit) with a federal IT governance design to change to a centralized IT governance design?