The rules of suspense are that you do know, and you just don't know when. In the Hitchcock rules of suspense, you are supposed to know that there is a bomb on the bus that might blow up, and then it becomes very tense - but if you don't know that there's a bomb and it just blows up, then it's just a surprise.
There's a lot of films that have relatively rigid road maps because they have a script and others that are less rigid because they have less of a script, like 'Elephant.' The road map becomes more interpretive, maybe, than one with a detailed script. Editing-wise, they all have their problems.