Here are some visual aids I came up with to help me envision the overall narrative shape of some of my novels.
First, this is the basic three-act, linear narrative that I used in The Astrologer and Cocke & Bull. The red arrow is the main story. The blue arrows are subplots. The angled yellow arrow is the level of tension/conflict:
Next we have the narrative structure I used in The Last Guest, which shows a linear central story interrupted by a series of disconnected character explorations, mostly in the form of flashbacks, that do little to further the action of the central story:
Lastly is the narrative structure I seem to be using for my work-in-progress, Go Home, Miss America. Essentially, action moves forward to the midpoint of the book when the characters are forced to change course and move toward the end of the book. There are overlapping segments of plot and theme. There are increasing amounts of tension. There are loopings backward in symbolism and character. It's by far the least straightforward structure so far, though perhaps my very first attempt at a novel was even less straightforward. Hmm. "We're going 'round in circles."
Of what use are these charts to you? None whatsoever. They are, in fact, of limited use even to me, the fella what wrote the books in question. But I think anything that helps a writer visualize the overall movement of the narrative is a good thing. Just this morning on the bus, I came up with a reassuring way of thinking about the second half of the book I'm writing. Reassuring ways of thinking are good. Every writer who's deep in the middle of a first draft needs reassurance. I'm at that point in the process where I no longer trust my judgment, and so I must trust my original impulses and ideas about the book. Once, many many months ago, this all seemed like a really good idea for a story. Just because I can't see it now, that doesn't mean it's not there. It always works out in the end, mysteriously enough.
Anyway, I am going to push the idea that this sort of graphing/mapping/charting exercise will be helpful to anyone writing long-form fiction, and will reveal things about the story to the writer that are hard to see otherwise. It also forces you to decide which narrative/story elements you think are most important, though certainly you can make many charts for a single novel. But it's not Schenkerian analysis and there are no rules. Give it a go, kids! It's fun and there's no wrong way to go about it.