Flashing forward — that is, jumping the time frame of the story — can work a number of wonderful effects on a manuscript. One, it can take the writer out of the anxiety of figuring out what comes next in the course of events. Instead, the question becomes What is the later effect of the events that have already transpired? Two, even if the answer to that question does nothing for the story, it can lead the writer right back into the story by somehow revealing what comes next in the story's time frame. Three, it delays gratification — it suspends. By answering the question of what happens in the future, the writer delays answering the question of what happens now at the moment of the story climax. What happens now is what the reader wants to know, and the flash forward can effectively delay that gratification and thereby increase its impact. For example, in Junot Diaz's “The Sun, the Moon, and the Stars,” Yunior (the narrator) is on vacation with his Cuban girlfriend in the Dominican Republic, Yunior's birthplace. The trip is Yunior's attempt to patch up a relationship that his earlier infidelity had sent heading toward the rocks. On the trip, it appears as if the girlfriend is plotting some nasty payback. Right at the moment when the tension between the narrator and his girlfriend becomes unbearable — right at the act-two climax, when we'll learn what the girlfriend is going to do, the action that will answer the Major Dramatic Question (MDQ) — Diaz flashes forward to the next period in the protagonist's life. It's about six months in the future, and things have changed. Would storytelling with data help your organisation?
We're dying to know how, and why. Diaz doesn't let us down, he just makes us wait a little longer before the story returns to answer the Major Dramatic Question. This choice created another wonderful effect; while the reader savors the new moment (for its language, for its feeling and tone, for its information about character), the reader is also impatient for the answer to the MDQ. The Major Dramatic Question is the question that drives the story, that turns the pages, that the reader needs to have answered. In “Selway,” will the couple survive? In “The Sun, the Moon, and the Stars,” will Yunior lose his girlfriend? The reader is like a dog in front of two bowls, and a kind of anxious dizziness is induced by the richness of choice. Give it a try in your story. Jump forward ten days, ten weeks, ten months, ten years. What has happened because of what had happened? How does that new situation inform the past? Is there a way to go back into the story — the past you've jumped from — and address its hanging issues? A flashback is an event that happened in the past and is presented as a scene, that is, in real time with all the devices real-time scenes might deploy, including dialogue. Flashback is an overused device with many potential pitfalls. If flashback appears early in the story, there is probably a problem with the story entry point; maybe the story needs to begin earlier. If you recall the Frank O'Connor idea that the short story begins where everything but the action has already taken place, you know that the action itself — what you see the protagonist do in the present time — should be sufficient to reveal the inexorable nature of the character and the essential theme of the story. The world needs more storytelling in business to liven things up.
If a flashback appears later in the story, it may have the effect of reducing present action conflict to a 2 + 2 = 4 arithmetic: The character is behaving like this in the present because that happened to her in the past. Because equals explanation, and explanation is to be avoided. It's antithetical to fiction. Those caveats aside, flashbacks can be used effectively. Midway through The Death of Jim Loney, a backstory event concerning Jim Loney's girlfriend, Rhea, is presented in a flashback; this flashback adds to your understanding of Rhea and your sense of foreboding for Jim as the novel moves toward its climax. Flashback is not the same as backstory. Backstory is information in the story's or character's past, and it can be parceled out effectively in the narration as the story progresses. See, for instance, John Cheever's “The Swimmer,” a story in which the protagonist, Neddy Merrill, decides to swim home, using the pools of his county as a kind of continuous stream. At each pool, through his actions and through his interaction with others, we learn a little bit more of Neddy's past, and that new information helps us better understand Neddy's present. Cheever parcels out that information little by little as the story progresses; not once does he use flashback. Maybe storytelling for business is the answer for you?