Recently I took an organisation to meet some development teams who were using Rational Tools and finding them really successful.
One area of pain for this organisation was the length of time development took. This started with lengthy requirements documents and lots of hand-offs between different departments in different locations.
When they asked about what the development teams did about lengthy documents. Their response was that they don’t write them anymore. Instead they used User Stories which represented ‘high level requirements’, these were then defined in detail closer to delivery.
For this team they found that using this approach it was easier to prioritise, fit in new important requests, reduce release cycles and have better visibility of progress.