What are the three agile planning layers in Focused Build, and how do they relate to each other?

Focused Build organises agile work in three nested layers:

1. Target release (top layer) — holds all build and deploy information for an overall release
2. Waves — define a block of functional scope; promoted to QA after customer sign-off
3. Sprints — time-boxed periods that deliver reviewable increments within a wave

A Q-Gate is a special milestone placed at a handoff point where stakeholders jointly decide whether to proceed to the next layer/phase.