Stage-Gate

What it is

Stage-Gate is a structured product development framework that divides the innovation process into stages (where work happens) separated by gates (where decisions happen). At each gate, a cross-functional team reviews evidence and makes an explicit go / kill / pivot / recycle decision before allowing the initiative to proceed.

Originally developed by Robert Cooper in the 1980s for physical product development, Stage-Gate has evolved through five generations. The 5th-generation model (current) integrates Agile practices, AI-assisted decision-making, and adaptive gates — it is not the rigid, waterfall process of earlier versions.

Companies using modern Stage-Gate achieve 63–78% product success rates, compared to ~24% for ad-hoc approaches (PDMA benchmarking studies).

Authoritative sources (external)

Resource	Executive summary (why it's linked here)
Stage-Gate International	Official Stage-Gate body of knowledge — Robert Cooper's framework, 5th-generation updates, research, and case studies. The authority for gate criteria and stage definitions.
5th-Generation Stage-Gate Model	Current evolution of Stage-Gate: iterative stages, Agile integration, lean gates, adaptive governance — addresses historical criticisms of rigidity.
PDMA — Stage-Gate 2026	Product Development and Management Association — practitioner community, research, and updated Stage-Gate guidance. Hosts Cooper's latest articles.

Core structure

Stages and gates

The classic 5-stage model, adapted for software products:

graph LR idea["Idea"] --> G0["Gate 0: Idea Screen"] G0 --> S1["Stage 1: Scoping"] S1 --> G1["Gate 1: Second Screen"] G1 --> S2["Stage 2: Build Business Case"] S2 --> G2["Gate 2: Go to Development"] G2 --> S3["Stage 3: Development"] S3 --> G3["Gate 3: Go to Testing"] G3 --> S4["Stage 4: Testing & Validation"] S4 --> G4["Gate 4: Go to Launch"] G4 --> S5["Stage 5: Launch"] S5 --> PIR["Post-Launch Review"]

Stage	Activities	Key deliverable
Scoping	Quick assessment: market, technical, financial, strategic fit	One-page opportunity brief
Build Business Case	Detailed investigation: user research, competitive analysis, concept testing, feasibility	Business case with evidence
Development	Design and build the product (via SDLC)	Working increment
Testing & Validation	Market testing, beta, usability, operational readiness	Validated product ready for launch
Launch	Market activation, GTM execution, scaling	Product in market

Gate decisions

Each gate uses explicit criteria — not opinions:

Decision	Meaning	Action
Go	Evidence meets criteria; proceed to next stage	Fund next stage, assign resources
Kill	Evidence shows the initiative should not proceed	Stop work, reallocate resources, document learnings
Pivot	Evidence suggests a different direction is more promising	Recycle to an earlier stage with revised framing
Hold	Insufficient evidence to decide; more information needed	Time-boxed investigation, then re-gate

5th-generation adaptations

Evolution	What changed
Agile integration	Stages use Agile/Scrum for execution; gates remain as strategic decision points
Lean gates	Gates are lighter, data-driven, and faster — not bureaucratic review boards
Spiral / iterative stages	Stages iterate internally (build-test-learn) rather than being strictly sequential
Adaptive	Gate criteria adjust based on project risk and novelty — higher risk = more rigorous gates
AI-assisted	AI can prepare gate materials, analyze market data, and flag risks — humans make decisions

Mapping to PDLC phases

Stage-Gate maps directly to PDLC phases and gates:

Stage-Gate	PDLC phase	PDLC gate
Gate 0: Idea Screen	—	Pre-P1 screening
Stage 1: Scoping	P1 Discover Problem	—
Gate 1: Second Screen	—	G1 (problem worth solving?)
Stage 2: Business Case	P2 Validate Solution + P3 Strategize	—
Gate 2: Go to Development	—	G2 (solution viable?) + G3 (invest in building?)
Stage 3: Development	SDLC A–F	—
Gate 3: Go to Testing	—	(SDLC Phase E exit)
Stage 4: Testing & Validation	SDLC E–F + P4 Launch (beta)	—
Gate 4: Go to Launch	—	G4 (ready to launch?)
Stage 5: Launch	P4 Launch (GA)	—
Post-Launch Review	P5 Grow	G5 (continue investing?)

Using Stage-Gate within this blueprint

Use templates/STAGE-GATE-REVIEW.template.md to document gate decisions. The template captures: - Gate identifier and date - Evidence reviewed (with links to artifacts) - Criteria assessment (met / not met / partially met) - Decision (go / kill / pivot / hold) - Conditions for proceeding (if any) - Resource allocation for next stage

Anti-patterns

Anti-pattern	Fix
Gates as bureaucratic checkpoints	Gates should be fast, evidence-based decisions — not multi-day review boards. If gates slow you down, make them leaner, not fewer.
Skipping gates for "urgent" projects	The riskier the project, the more you need gates. "Urgency" is not evidence of viability. Adapt gate rigor, don't skip.
Gates without kill authority	If a gate never kills a project, it's theater. Empower gatekeepers to say no. Track kill rate as a health metric.
Waterfall stages	Use Agile execution within stages. Stage-Gate provides strategic decision points; stages are iterative, not sequential waterfalls.

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