Agile involves (among other things) cross-functional teams, high-bandwidth communication, and adaptive planning. We know the best ways of achieving these things. The details vary, but when it comes to broad strategy, I don’t think there’s even any debate any more.

• We know that the most effective way for business experts, programmers, and testers to collaborate is to put them on a single team that shares responsibility and authority for success.
• We know that the most productive way for teams to work together is to sit together in a shared workspace and communicate primarily via ad-hoc face-to-face discussion.
• We know that the most successful way for teams to meet market needs is to adjust their plans as they go, forgoing detailed long-term plans in favor of rapid feedback and maximizing throughput and value.

We know this, and yet it rarely happens.