Figuring out what you need to deliver is often a subproject all it's own. I used to work at a place that did a lot of fixed-price consulting work and we were sm

Figuring out what you need to deliver is often a subproject all it's own. I used to work at a place that did a lot of fixed-price consulting work and we were small enough that if we blew a bid badly, we were basically dead. We'd often look at the big picture of what the client wanted and offer to break that down into a detailed design and project plan which they could then pay us to implement or hire someone else to do. We used that as an opportunity to figure out what they really wanted/needed.