5.2 Component Genealogy

Genealogy is the forensic DNA of your product. While "Traceability" tracks where a unit went (Location), "Genealogy" tracks what went into it (Composition). Without a precise parent-child linkage, a defect in a $0.10 capacitor forces you to recall $10M of finished inventory because you cannot isolate the specific serial numbers containing the bad batch.

The Hierarchical Data Structure

Do not flatten genealogy into a single text field. Structure it as a relational tree to handle multi-level assemblies.

The Tree Logic

Root: Finished Good Serial Number (Parent).
Branch: PCBA Serial Number (Child).
- Leaf: CPU Lot Code (Grandchild).
- Leaf: Resistor Reel ID (Grandchild).
Branch: Housing Lot Code (Child).

Integrity Rule

If a Child is "Scrapped" in the system → The Parent must automatically lock.
If a Child is "Quarantined" → The Parent is flagged "Hold".

Panelization & Inheritance Logic (The "Split")

In SMT, you build Panels (Arrays), but you sell Boards. The MES must handle the "Divorce" of the Panel ID and the "Birth" of the Unit IDs without losing history.

The Inheritance Flow

Panel Phase (Parent): Components are consumed against the Panel ID.
- Record: Panel-123 contains Reel-A.
Depanelization Event (The Split): The router/saw cuts Panel-123 into 4 distinct units (SN-1, SN-2, SN-3, SN-4).
Data Cloning: The system must copy the genealogy of Panel-123 to all 4 children.
- Result: SN-1 contains Reel-A; SN-2 contains Reel-A, etc.

The "X-Out" Handling (Bad Board Logic)

Scenario: A 4-up Panel has one bad PCB (marked with a black dot/X).
Logic:
- If Panel has X-Out at Index 3 → Do Not Generate SN for Position 3.
- Or: Generate SN-3 but immediately set status to Scrap.
- Risk: If you generate a "Good" SN for a bad board, it might leak into the casing process.

Collection Granularity (Risk-Based)

Tracking every washer creates "Data Noise." Define scope based on component risk.

Class A: Critical / Safety (Serialize)

Definition: High value (CPU) or Safety Critical (Airbag Sensor).
Method: Unique Serial Number scan (1-to-1).
Logic: Unit-A contains exactly CPU-SN-99.

Class B: Functional (Lot Trace)

Definition: Functional components (Capacitors, ICs, Glues).
Method: Batch/Lot ID scan (Many-to-1).
Logic: Unit-A contains Capacitor-Lot-99 (shared with 5,000 other units).

Pro-Tip: For SMT lines, never scan individual boards for Class B parts. Scan the Reel when loading the Feeder. The MES maps "Reel A was on Feeder 1 from 10:00 to 12:00" and inherits the Lot Code to all Panels produced in that window.

Validation at Point of Scan

Genealogy is an active control. Validate the component before installation.

The "Three-Way Match"

Upon scanning a component, verify:

BOM Match: Does this Part Number belong in this BOM?
AVL Match: Is this Manufacturer on the Approved Vendor List?
Status Match: Is the Lot valid (Not Expired, Not Quarantined)?

Expiration Control Logic

Context: Solder Paste, Epoxies.
If (Current Time) > (Material Expiry Date) → Lock Machine.
If (Current Time) > (Material Open Time + Pot Life) → Lock Machine.

The Rework Problem (Divorce & Remarriage)

Genealogy is fragile during rework. When a technician swaps a part, the system must "amputate" the old limb and "graft" the new one.

The Swap Workflow

Un-Marry: Operator scans Unit SN -> Selects "Remove Component X".
- Action: Link broken. Component X marked "Consumed/Scrap".
Re-Marry: Operator scans New Component Y.
- Action: New link established.
Audit: History shows both: "Component X (Removed) -> Component Y (Installed)."

Final Checklist

Category	Metric / Control	Threshold / Rule
Structure	Hierarchy	Multi-level Parent/Child support (Not flat text)
Panelization	Inheritance	100% of Panel Data cloned to Child Boards
Panelization	X-Outs	Bad Board positions blocked from generating "Pass" SNs
Scope	Class A (Critical)	100% Serialized (1-to-1)
Validation	BOM Interlock	Block scan if P/N not in BOM
Rework	Swap Logic	"Un-marry" event required before new scan
Integrity	Completeness	Shipping Blocked if Genealogy count < BOM Qty