For a reader to enjoy the story, something has to change. Maybe it's the plot changing the character's world. Or maybe it's the character that changes. Or even both.
But something has to change. Because if it doesn't, and everything goes back to how it was before the start of the story, what would be the point? Why would a reader sit through the thousands of words in between?
So during revisions, you might want to see if your characters grew. Especially if you're more of a plot driven kind of writer. It's something I find quite a lot, that the plot-driven stories have awesome development in the plot, but almost none in the character. In fact, they can potentially let characters go through the motions required by the plot and leave the characters relatively unchanged. (And in some action-books I've read, unscathed.)
On the other hand, character-driven writers tend to have excellent character development, but the plot development is a bit lacking. I actually think it's easier for a character-driven writer to get both right, because a character can't change if something didn't happen to him or her. Still, the plot aspect to the story might feel murky or undefined. As if something happened, but the reader can't be sure.
Both of these can be acceptable if it's what you're going for. If not, you might want to spend a revision round either defining what's going on inside the character, or outside around the character.
More specific than that, I can't really help you, since it depends on the story. But if you have development issues in your story, you can contact me and I'll go through your work to see if you can improve on character or plot development. Otherwise, you should have a crit partner who's able to help you out.
Look Out for These:1) Plot feels like it's going nowhere, even if it is in fact moving towards a point.
2) The plot is full of events, but the character seems to have learnt nothing, or didn't change, or seems largely unaffected.
3) Plot development: Crit partners say that you have pacing issues, but deep down you know the pacing is fine.
Are you a character or plot-driven writer? Do you find yourself having to go back to make sure the development of plot and/or characters need to be better defined?