https://scaledagile.com/what-is-safe/
It has 10 principles:

  1. Take an economic view
  2. Apply systems thinking
  3. Assume variability; preserver options
  4. Build incrementally with fast, integrated learning cycles
  5. Base milestones on objective evaluation of working systems
  6. Make value flow without interruptions
  7. Apply cadence, synchronize with cross-domain planning
  8. Unlock the intrinsic motivation of knowledge workers
  9. Decentralize decision-making
  10. Organize around value