Here's a typical role and hand-off sequence that I encounter in "waterfall" shops:
Customer -> Business Analyst -> Developer -> Tester
And then they learn about Agile so the sequence changes to this:
Customer -> Business Analyst -> Tester -> Developer -> (Business Analyst + Tester)
... which really misses the point. We're not just re-ordering hand-offs, we actually want to remove them.
What I'm looking for is a sequence that looks more like this:
(Customer + Business Analyst + Tester + Developer) -> (Tester + Developer (referencing Business Analyst and Customer as useful)) -> (Customer + Business Analyst + Tester)
If the Customer time is constrained,
Customer -> (Business Analyst + Tester + Developer) -> (Tester + Developer) -> (Business Analyst + Tester) -> Customer