Not every project requires an AFE. They're generally used for larger expenses or projects with a significant impact—smaller tasks might not need one.
Yes, an AFE can be amended if circumstances change. Just like adjusting your plans when the weather turns, you can tweak the AFE to fit new needs.
The approval time for an AFE can vary. It's usually a matter of days, but it can take longer if the project has a lot of moving parts or requires extra scrutiny.
Typically, the AFE needs to be approved by higher-ups in your organization or specific budgeting teams. It's all about getting the thumbs up from the right people.