Only 13% of respondents in larger organizations (more than 500 employees) said that nearly all their projects used agile. In these larger companies, respondents said that lack of management support (27%) and “general resistance to change” (26%) were major barriers to agile adoption. Conversely, among smaller companies, the vast majority (nearly 75%) of projects used agile and only 10% of respondents cited lack of management support or “general resistance to change” as an issue or barrier to adoption.

via State of Agile Development Survey Results

The living prototype serves the same purpose and should be supportting document to the story. In practice, the living prototype enables the team to spike difference concepts. As the design matures, a common UI framework emerges, as illustrated in diagram.

via Agile Experience Design - A Digital Designer’s Guide to Agile, Lean, and Continuos