Great post! One of the challenges I often see for product teams is that when marketing decides what features go into releases (this is small, but influential number of IT projects). Marketing folks, while being intelligent and hard working, become fickle-minded when given such freedom (conflicting customer demands, competing products, need to differentiate etc) and start to make changes to the well-understood backlog.

Another challenge are the dependencies of some user stories on other stories – without understanding dependencies and establishing a “platform” of basic features, it becomes very hard for the project team to deliver in a cadence. A DSM can help resolve some (not all, of course) of the dependencies and can contribute to the analysis of the product backlog, thus enhancing the knowledge of the team.