The first phase of a movie production is called development. This is the period in which the screenplay is written. At this point in time, a producer may or may not be already attached to the project. If the screenplay is a spec script, then the screenwriter is writing it on his own, without any guarantee that he will ever sell it. If the writer is in a work-for-hire system, then he's getting some money for his time.
The development phase can be the shortest or the longest phase in a production. In The Curious Case of Benjamin Button, for instance, the short story in which the movie is based on was published in 1922, with the rights for a movie being first acquired in the mid-1980s. Between this first purchase and beginning of the official pre-production, several directors and stars were attached to the project. In 2008 the movie was first released with David Fincher as the director and Brad Pitt in the main role.
This lengthy period before pre-production starts is often called "development hell."
Development hell is a media-industry jargon for a film, television screenplay, computer program, concept, or idea becoming and remaining stuck in development and taking an especially long time to start production, if ever. The film industry buys rights to many popular novels, video games, and comics, but it may take years for such properties to be successfully brought to the cinema, and often with considerable changes to the plot, characters, and general tone.
Film Professor's Insight
Finding good, easy-to-produce scripts is hard and complicated. Students never buy scripts because the rights are expensive. Usually they write the themselves or ask someone else to write.
When selecting a script, you should always consider length, the number of locations and of characters. This is necessary because you want to make sure that you are able to finish the film without going over budget. A script with five locations and five characters might be too much. If you are shooting actual film (like 16mm), you probably will choose a story with one location and maybe two or three characters. Learn the benefits of shooting film.