I suspect this is the area in which most stories fail. Because the structure is not readily visible in a story that works—although you certainly notice when it's not there—readers might pin a tale's success on character development or a fascinating world or beautiful writing. Fortunately, writers and storytellers have been wrestling with problems of story structure since, well, forever, and some very successful practitioners have written about it so that we can learn from their experience. Here are a couple links to articles to wet your appetite and start thinking about the load-bearing walls holding up your stories.
David Farland's Daily Kick in the Pants—Plots
David Farland (a pseudonym of Dave Wolverton) is an American science fiction and fantasy writer best known for his Runelords series. In this concise article, Farland lays out the importance of tension and try-fail sequences.
The biggest problem with plots is that the author leaves one or more elements missing. Usually the author gets a character in there—even more than one, but something gets left out.
The Lester Dent Pulp Paper Master Fiction Plot
Lester Dent was an American novelist who penned over 150 novels and is best known as the creator and primary author of the Doc Savage series. Dent's master plot outlines the structure for 6000 word pulp stories, but I suspect the principles could be applied to longer pieces.