Frequently Asked Question
Stage-gate structure
Product development should advance through explicit evidence gates rather than through calendar dates alone. Gate 0 — opportunity and charter: confirm the user problem, business case, stakeholders, constraints, project scope, and accountable owner. Gate 1 — concept: approve the voice of customer, measurable requirements, critical-to-quality characteristics, candidate concepts, initial architecture, feasibility evidence, and the risk plan. Gate 2 — design baseline: approve the controlled design configuration, interfaces, tolerances, special characteristics, DFMEA actions, DFM/DFA review, verification plan, and change-control baseline. Gate 3 — validation and industrialization: approve production-intent verification and validation, reliability evidence, process flow, PFMEA, control plan, measurement capability, tooling, and pilot-build results. Gate 4 — release and launch: approve the released configuration, residual-risk decision, training, service information, traceability, and launch-readiness evidence.
| Gate | Decision question | Required evidence |
|---|---|---|
| 0–1 | Is the problem worth solving and is the concept feasible? | Charter, VOC, requirements, concept trade study |
| 2 | Is the design controlled and ready for formal verification? | Design baseline, interfaces, DFMEA, verification plan |
| 3 | Does the product work in representative use and can it be produced? | Validation, reliability, PFMEA, control plan, pilot |
| 4 | Is release safe, controlled, and supportable? | Approvals, residual risk, configuration, launch plan |
Worked example
For a sealed enclosure, Gate 1 needs measurable ingress, thermal, service-access, and cost requirements. Gate 2 needs the selected wall thickness, gasket interface, fastener strategy, DFMEA actions, and test method. Gate 3 needs production-intent units and a representative environmental test. If leakage occurs, the gate remains open until the cause, correction, and retest are documented. A schedule milestone cannot substitute for objective evidence.
Gate discipline: record the configuration reviewed, open actions, owner, due date, assumptions, and decision authority. Red/yellow/green status is only a summary; the evidence remains the decision record.
Required gate sign-off
Each gate requires a named decision owner and functional sign-offs on the evidence, not merely a status color. The signatories below are a minimum governance pattern; add regulatory, safety, service, supplier, or customer approval when the product requires it.
| Gate | Minimum deliverables | Required sign-off |
|---|---|---|
| 0 — opportunity | Problem statement, charter, business case, stakeholders, constraints, initial risk | Project sponsor, product owner, engineering lead |
| 1 — concept | VOC, CTQs, measurable requirements, concept trade study, feasibility, initial DFMEA | Product owner, systems/design lead, manufacturing lead, quality |
| 2 — design baseline | Controlled configuration, interfaces, tolerances, special characteristics, DFMEA actions, verification plan, DFM/DFA review | Design authority, systems, quality, manufacturing, supply chain as applicable |
| 3 — validation and industrialization | Verification/validation, reliability, pilot results, PFMEA, control plan, measurement capability, open-risk disposition | Design authority, quality/validation, manufacturing/operations, regulatory or customer as applicable |
| 4 — release and launch | Released configuration, residual-risk acceptance, change-control baseline, training, service information, traceability, launch plan | Project sponsor, design authority, quality/regulatory, operations, service |
A gate may be approved, approved with documented conditions, held pending evidence, or stopped. The decision record should include revision, date, attendees, open actions, owners, due dates, deviations, and the authority accepting residual risk.