3.2 Serialization and Identity Lifecycle

Logic: Pre-Printed vs. On-Demand

• If usingSN Pre-Printedcontains Labelsspecial characters (Vendor/, Supplied)\, :) → Vendor must provide a Manifest File (CSV/XML)Then containing all SNs. MES imports this file and marks them "Available."
• If using Print-on-Demand → Printer requests next SN from MES API. MES marks it "Printed" immediately.

Syntax and FormatReject. (TheThese Structure)

RandomURL numbers are useless to humans; sequential numbers are guessable. Use a structured hybrid approach.

Recommended Format

[Product Family] - [Date Code/Rev] - [Sequence]

• Example: A01-2401-00123 
  • A01: Product Type A.
  • 2401: Jan 2024.
  • 00123: Base-10 or Base-36 Counter.

Format Rules

• Avoid: Ambiguous characters (O, 0, I, 1, Q).
• Avoid: Intelligent logicstrings in theweb-based sequence itself. Do not embed "Color" in the serial number. If the color changes (Rework), the SN becomes a lie.
• Barcode: Use DataMatrix (ECC200) for PCB/Components (Small, robust). Use Code 128 for Cartons (Readable by legacy scanners)reporting).

IdentityThe Lifecycle StatesState Machine

An IDIdentity existsis not static. It moves through distinct states.

1. Create (Minting)

The generation of the string in definedthe states.database.

• Rule: The Unit_ID column must behave strictlya controlled.
  UNIQUE

  State Definitions

  1. Generated: Number exists in DB. Not yet physically assigned.constraint.
  2. Printed:Risk: Physical"Ghost labelIDs". created.If (Riskyou zone:pre-print 1,000 labels and the printer jams, you have 50 "Created" IDs that do not exist physically.
  3. Control: If Label mightis bedestroyed lost→ beforeThen sticking)scan to "Void/Scrap" immediately.

2. Assign (Binding)

The moment the ID is physically applied to the hardware.

• Laser Marking (Preferred): Laser requests ID from MES → Marks Board → Verify Read. If Read Fail → Then Reject Board (Do not assume mark is good).
• Commissioned (Birth): Label scans at the first station. Digital Link created between SN and Work Order.
• Scrapped (Death): Unit destroyed. SN is "Burned" and cannot be reused.
• Shipped: Unit left the building. Ownership transferred to Customer.

Duplicate Protection Logic

• IfLabeling: Operator scans SNLabel 123→ atMES links Label to Production Order.

3. Split (Depaneling / Inheritance)

In electronics, you manufacture a "Start"Panel" station(1 Parent) containing multiple "Circuits" (N Children).

• The Problem: Reflow data belongs to the Panel. The customer buys the Circuit.
• The Logic:
  • Step 1: Track Panel_ID through SMT.
  • Step 2: At Depaneling (Router), trigger the Split Event.
  • Step 3: MES auto-generates Circuit_IDs (if not pre-marked) or reads existing Circuit_IDs.
  • Step 4: Inheritance: All process data (Temperatures, Times) from Panel_ID is copied/linked to every Circuit_ID.

4. Merge (Aggregation / Packing)

The inverse of splitting. Grouping individual units into a parent container (Tray, Box, Pallet).

• Logic:
  • Scan Box_ID (Parent).
  • Scan Unit_IDs (Children).
  • Constraint: If Unit_ID status ≠ "Passed" → CheckThen State.Block adding to Box.
• IfTraceability: StateThe =Box_ID "Commissioned"becomes the proxy. Scanning the Box reveals all contained Units.

5. Reassign (AlreadyCarrier Active)Logic)

→

Distinguish between BlockProduct (Duplicate).

• IfID State(Immutable) = "Shipped" (Ghost Unit) →and BlockCarrier ID (Return Merchandise Authorization required)Reusable).

Label Printing & Validation

Printing is the bridge between the digital and physical worlds. It is the most common point of failure.

The "Print-Verify" Loop

Never assume a label is readable just because the printer didn't jam.

• Equipment:Product ID: UseOnce printersassigned, withit internalnever verifiers (ODV) or place a fixed scanner immediately afterleaves the printproduct.
• Carrier head.ID (Pallet/Tray): Can be unbound.
• Logic: If Unit is removed from Carrier → Then Break the Link (Carrier_ID = Null).

6. Relabel (Damage Control)

Labels get damaged. Replacing them is a high-risk operation.

• The Cardinal Rule: Never generate a new identity for an existing product. You must reprint the original SN.
• Procedure:
  1. Supervisor authenticates.
  2. Operator scans old 2D code (if readable) or manually enters SN.
  3. MES validates status.
  4. Printer produces Duplicate label.
  5. Audit Log: Record "Reprint event for SN:123 by User:ABC".

7. Scrap (The End)

When a unit is physically destroyed, its digital twin must die.

• Action: PrintTransition Label.State to "Scrapped".
• Action:Constraint: Scan Label.
• If ScanSN Failis Scrapped → VoidThen Block all future processing.
• Re-Use: Never recycle the SN inof Systema scrapped part. It is burned forever.

8. Rework (The Loop)

Sending a unit back to a previous step.

• Logic: + Reprint New SN. Do not retrydelete history. Append new history.
• State: Transition to "In Rework".
• Validation: When rework is done, the sameunit SNmust ifre-pass the physicalQuality label is bad.