3.1 NPI stage gates: commercial & technical

New Product Introduction (NPI) is the highest-risk phase in the manufacturing lifecycle. It is where margins are engineered or destroyed. A failed NPI phase results in “unstable equilibrium”—a product that can be built, but never profitably or predictably. A strict Stage-Gate process is used to enforce discipline. There is no “drift” into production; specific gates are passed with binary (Pass/Fail) criteria.

The gate logic

The process is divided into 4 standard phases: Engineering Validation Test (EVT), Design Validation Test (DVT), Production Validation Test (PVT), and Start of Production (SOP).

Rule: A project cannot advance to the next stage until the Exit Criteria of the current stage are formally signed off. “Conditional Approvals” are strongly discouraged, as they act like technical debt that accrues interest, usually resulting in yield loss during production.

Gate 0: project kickoff & commercial entry

Objective: Validate that the business case exists and the technical data is intelligible.

• Owner: Sales / Account Manager

Entry Criteria (Inputs):

• Golden Data Pack: Complete Bill of Materials (BOM), Gerber files, Assembly Drawings (See Ch 1.2).
• Commercial Coverage: Non-Recurring Engineering (NRE) Purchase Order (PO) received for EVT build.
• Target Pricing: Agreed Target Price vs. Estimated BOM Cost gap is < 10%.

Exit Criteria (Outputs):

• Project Schedule: Timeline locked with customer (T0 to SOP).
• Long Lead Items (LLI): Risk buy Purchase Order (PO) placed for components with lead time > project duration.
• Team Assignment: Project Manager, Lead Engineer, and Buyer assigned.

Pro-Tip: Engineering work must not be started without a Purchase Order (PO) or a signed Letter of Intent. “Goodwill” does not pay for engineering hours.

Gate 1: EVT (engineering validation test)

Objective: “Does it work?” Prove the design intent and basic functionality.

Volume: Small (5 – 20 units).

Method: Soft tooling, manual assembly, quick-turn.

• Owner: Lead Engineer

Entry Criteria:

• Draft Bill of Materials (BOM) loaded in ERP.
• Primary components available.

Exit Criteria:

• Functional Pass: Units power on and perform primary functions.
• DFM 1.0 Report: “Showstoppers” identified (e.g. impossible solder joints, component collisions).
• BOM Scrub: Obsolete/High-risk parts identified.

Gate 2: DVT (design validation test)

Objective: “Is it robust?” Finalize the design and materials. The product must meet all regulatory and reliability standards.

Volume: Medium (20 – 100 units).

Method: Hard tooling (molds) initiated, production-intent components.

• Owner: Quality Manager / Engineering

Entry Criteria:

• Design Freeze: No new features added after this point.
• Test Plan: Draft Functional Testing (FCT) procedure defined.
• Tooling: Molds/Fixtures ordered.

Exit Criteria:

• Regulatory Pass: CE/FCC/UL certification samples pass.
• Reliability Pass: Thermal, Drop, and Vibration tests passed.
• DFM 2.0: All “Red” issues from Engineering Validation Test (EVT) resolved.
• Test Fixture: Beta Functional Testing (FCT) fixture operational.

Decision Logic:

• BOM changes exceeding 20% during this phase necessitate repeating Design Validation Test (DVT). Under these conditions, the project cannot proceed to Production Validation Test (PVT).
• Hard Tooling modifications require triggering the Tooling Modification Approval (TMA) process.

Gate 3: Production Validation Test (PVT)

Objective: “Can we build it at scale?” Test the manufacturing line, not the product. Validate cycle time and yield.

Volume: Pre-production run (50 – 500 units).

Method: Production line, standard operators, final test fixtures.

• Owner: Operations Manager / Plant Director

Entry Criteria:

• Supply Chain: Material pipeline clear for Mass Production.
• Work Instructions: Standard Operating Procedures (SOPs) written and posted.
• Test Limit: Pass/Fail limits locked in the tester.

Exit Criteria:

• Yield Target: FPY (First Pass Yield) ≥ 95% (or agreed target).
• Cₚₖ/Pₚₖ: Critical dimensions demonstrate statistical control (Cₚₖ ≥ 1.33).
• Cycle Time: Line moves at the quoted TAKT time.
• Golden Sample: Signed “Master Unit” stored in Quality Assurance cage.

Pro-Tip: Fixing a physical unit on the manufacturing line during PVT without formally recording the root cause constitutes a failure of the PVT objective. PVT is designed to expose process failures, not to mask them.

Gate 4: SOP (Start of Production / Mass Production)

Objective: Release to volume manufacturing. Transfer ownership from Engineering to Operations.

• Owner: Operations Manager

Entry Criteria:

• PVT Sign-off: All critical open issues closed.
• Commercial Lock: Volume PO received; Pricing/Terms finalized.
• RMA Process: Defined and agreed upon.

Exit Criteria:

• Shipment of first commercial lot.

Final Checkout: NPI stage gates (commercial + technical)

Gate	Critical Control Point	Pass State	Owner
G0 (Kickoff)	LLI Orders	Purchase Orders (POs) placed for Silicon/LCDs/Connectors.	Sales
G1 (EVT)	DFM Report	Critical design flaws highlighted to customer.	Engineering
G2 (DVT)	Design Freeze	Customer signs off “No more changes.”	Engineering
G3 (PVT)	Yield Stability	Three consecutive lots met yield target.	Operations
G4 (SOP)	Test Limits	Test software version locked (Read-Only).	Quality