To create a successful film the producer needs to be clear about the whole narrative from the beginning to end. They must know how the story with pan out and how it will develop.
The most simplistic way of explaining narrative structure is:
Beginning – Middle- End
Beginning – At the beginning there is a state of equilibrium. This is when things are at peace. This then represents normality for the main characters.
Middle-something in the narrative will happen to disrupt the equilibrium and cause a state of disequilibrium. This makes up most of the storyline of the film.
The End- At the end the narrative is restored back to normality. The story then is resolved or a new state of equilibrium is achieved.
Therefore you can say the structure is like:
Equilibrium- Disequilibrium- Equilibrium
A more complex way of looking at it is:
I have looked at an example for 'Scream':