The need for assumptions

Lean UX isn't focused on detailed deliverables. Instead, it is focused on producing changes that improve the product in the present. In practice, you are replacing "requirements" with a "problem statement", leading to a set of assumptions that can result in a hypothesis. Assumptions are generated on a workshop basis.

It is understood that assumptions may not be correct and can change as better understanding develops. The team will prioritise assumptions by the risk they represent—the more severe the consequence, the higher the priority.