Principles

• Constant Feedback — XP: Constant Feedback / Lean: Learn & Improve, Seek Perspective / UCD: The Process is Iterative
• Diverse Team — XP: Diversity with Skills and Perspectives / Lean: Empower the Team, cross functional team, right resources / UCD: Multidisciplinary skills and perspectives
• Small Chunks of User Value — XP: Flow and Baby Steps / Lean: identify the value stream, reduce waste, define value to customer in small chunks / UCD: Address the whole user experience, understand users, involve users throughout the process
• Self-similarity — Use similar structures, don’t start from scratch if you don’t have to
• Humanity — We are humans building products for humans
• Shared Responsibility — across the whole team

Reference:

https://medium.com/@ryanjjones10/what-is-the-pivotal-process-417fab075f4f