Stage 6 — Phase Gates

SRR, SDR, PDR, CDR readiness with entry/exit criteria assessment.

The final synthesis stage produces phase-gate readiness assessments. This is the artifact that tells you whether the design package is mature enough to pass each of NASA's standard milestone reviews.

The four gates (Phase 1)

Gate	Acronym	What it certifies
System Requirements Review	SRR	Requirements are complete, consistent, and verifiable
System Design Review	SDR	A coherent baseline architecture exists
Preliminary Design Review	PDR	The design is sufficiently mature to start fabrication of long-lead items
Critical Design Review	CDR	The design is complete; fabrication can begin in full

Higher Phase numbers (Phase 2 = operations, Phase 3 = disposal) have their own gates, which Blueprint doesn't currently model.

What each assessment contains

For each gate, the readiness assessment captures:

Entry criteria — what should be true before this gate is attempted, and Blueprint's assessment of whether the current artifact set meets each criterion
Exit criteria — what the gate must produce, and whether the artifacts cover it
Recommended actions — items the team should address before attempting the gate

How to read it

NOTE

The phase-gate assessment is Blueprint's opinion on readiness. Real
gate reviews involve human review boards. Use this as a self-audit
checklist before convening the actual review.

Read top-to-bottom: SRR → SDR → PDR → CDR. Each gate's "Recommended actions" tells you what to fix before attempting that gate.

A typical first-run assessment shows:

SRR — usually meets most criteria if requirements are well-defined
SDR — meets most criteria if decomposition has full DTR coverage
PDR — partial; usually flags interfaces and verification activities that need more detail
CDR — usually shows substantial gaps; that's expected — CDR-ready requires test data and prototype results that Blueprint can't produce

Limitations

Blueprint's phase-gate assessment is structural — it checks whether the artifact set has the right shape. It does not:

Verify technical correctness (a wrong requirement still counts as a requirement)
Assess maturity beyond what's in the artifacts (e.g. it can't tell you whether your propulsion subsystem is actually viable)
Replace the human review board

The assessment is a checklist for you to use; the Engineering Disclaimer applies in full.

End of the pipeline

After phase gates, the Render stage assembles all artifacts into the final bundle. See Reading your first artifact bundle.