For those who would like to see a sample requirements document, with use cases sketched out at several levels, I posted one as the Oct 11, 98 update at http://members.aol.com/acockburn (can now be found at http://alistair.cockburn.us/index.php/Sample_system_requirements_document ). I got many of the non-obvious questions from the requirements document template posted by SuzanneRobertson? of the AtlanticSystemsGuild?. However, hers had 36 chapters, and while thorough, was too intimidating to fill out on a less-than-critical project. So I abridged that and put it into a form I would be willing to stand working with. You will see it is still fairly intimidating for a casual project, but has some interesting questions for any project's starting staff to ponder. I am thinking of moving the use cases to the end, since they form most of the bulk. Comments welcome (that's why I posted the document and this note) --AlistairCockburn
To present an alternative to Alistair's Requirements doc (which looks pretty good), this outline is based loosely on the IEEE Standard. 830-1998 IEEE Recommended Practice for Software Requirements Specifications.
Software Requirements Specification (SRS)
See also anecdote about TypesOfProjects