Recently I’ve (completely by accident ;D) read latest book of Gojko Adzic (author of well-known and commonly praised "Specification by Example") - "Impact Mapping" (http://www.amazon.com/Impact-Mapping-software-products-ebook/dp/B009KWDKVA). Ok, it wasn’t really an accident: Gojko (http://en.wikipedia.org/wiki/Gojko_Adzic) is an expert in TDD, BDD and general agile methods, so books he publishes are usually more than just worth a read.
- You don’t start with "shopping list" - exactly the opposite (having clients designing solutions instead of us is one of our greatest sins!)
- The goal is a root of everything. This way you make sure you won’t lose it.
- Products are the answer to all the preceding questions (WHY? WHO? HOW?).