The three ways you can collect use cases

Well, you basically choose three ways:

1. Collect them according to what you designate as their needs

What? Are you crazy? This is your costumers business, not yours! Who the hell told you that you knew better than your costumer what are their business rules? Wake up, this is the way most failed projects took!

2. Collect them according to what your costumers designates as their needs

What's wrong with you? If your costumers knew what he wanted, why would they hire you as a consultant? Weenie! Get real! This is a great way to spend your costumers budget releasing low value.

3. Collect them according to what your costumers need

There, was it that hard? Your job is to dive into your costumers business, adding value to it. Your costumers know what's best for their business, but often they don't know how to express it, so one of your greatest responsibilities is to take it from them - notice how we use the term 'capture'? And they don't really have to know how to express it - that's not their business, that's yours.

You're the project's advocate (please don't confuse with the costumer's advocate). You're also some kind of psychoanalyst, in the sense you must help them extracting information they and only they hold deep down inside - and lookout, for them, this information they didn't give you is always obvious. You're the guardian of the project conceptual consistence. You're the one that will propose and negotiate changes in order to release more of the project's value. Your the one that has to guarantee it all sticks together.

Is this simple? Hell, no! But it's your job!

Do you need some hints? Sorry, no Silver Bullet here. Try avoiding the first 2, be sure to involve the key users, know as much of your costumers business and processes as you can, be sure to be as assertive as you can, embrace the problems as soon as they arise (don't hold them back from your costumers as you did as a kid), privilege proven practices, use good judgment, don't be afraid to backtrack when you're wrong, and above all, stop loosing your valuable time reading blogs like this one looking for the Holy Grail! The answer lyes between you and your costumers. Go find it!