The Product Owner is responsible for putting the Features and Stories in the Backlog. The Team works with the Product Owner during Backlog Refinement to help Product Owners get the stories into actionable shape.

Backlog refinement is usually the first time that the Team can work though an understanding of dependencies associated with the work, be they internal (e.g. availability of specialists or systems) or external (e.g. need for something from a supplier).

The main thing to achieve is to ensure that we understand how the dependency lines up with Iteration (Sprint) timing. For example, if an external dependency with a supplier is expected to be resolved in 2 months time, then it probably doesn’t make sense to prioritize our work so that it would be scheduled for the upcoming iteration. You might as well wait until the value can be delivered and, in the meantime, deliver other valuable stuff (control WIP by “stop starting, start finishing”).