Serialization – Unit/Case/Pallet IdentificationGlossary

Serialization – Unit/Case/Pallet Identification

Q: What happens during rework?

Affected units or cases are disaggregated, non-conforming serials decommissioned, replacements commissioned, and the aggregation tree rebuilt before release.

Q: How do EPCIS and ASNs relate?

EPCIS communicates serialized events and relationships while the ASN communicates shipment and packaging details; together they keep physical and digital twins synchronized.

Q: Which barcode should we use?

Follow GS1 guidance: GS1 DataMatrix for units, GS1-128 for cases, and SSCC labels for pallets. Device UDI adds specific composition and placement rules.

This topic is part of the SG Systems Global regulatory & operations glossary.

Updated October 2025 • GS1 Identification, Aggregation & Traceability • Packaging, QA, Supply Chain

Serialization assigns globally unique identities to saleable units, cases, and pallets, and keeps those identities connected as product moves through manufacturing, packaging, warehousing, distribution, and returns. At the unit level this typically means a product identifier (e.g., GS1 GTIN) plus variable data (lot/batch and expiry) and a unique serial number, encoded in a 2D or linear barcode and verified at pack. Cases carry content identity and counts, usually via GS1‑128 with Application Identifiers and a case serial; pallets (logistics units) are labeled with an SSCC. The resulting parent‑child relationships (unit→case→pallet) are published and consumed across the supply chain—often using the EPCIS Traceability Standard—to prove pedigree, enable rapid recalls, and block diversion or counterfeits. Effective serialization is inseparable from Label Verification, disciplined Lot Traceability, and event‑driven warehouse execution in the WMS.

“Serialization turns every pack into a passport—and aggregation binds those passports together so you can trust what’s inside the case and pallet.”

TL;DR: Serialization creates unique identities at unit, case, and pallet levels and preserves their relationships. Units are commissioned and verified on the line, aggregated to cases and pallets, and shipped with ASNs and EPCIS events. The program rides on controlled master data (GTIN, packaging hierarchies), validated systems (CSV, Part 11/Annex 11), line vision checks, and audit trails. Downstream, the WMS enforces parent‑child integrity, FEFO, and scan‑based loading at the dock.

1) What Serialization Covers—and What It Does Not

Covers: Unique identification of saleable units, cases, and pallets; barcode symbologies and data structures; commissioning, aggregation, shipping, receipt, and returns events; and the electronic exchange of those events with partners. Serialization strengthens recall readiness, deters diversion, and supports regulatory reporting. It also reduces operational risk: when parent‑child links are trustworthy, cases can be scanned without opening, and pallets can be verified at the dock without breaking down.

Does not cover: Serialization does not prove product quality by itself, nor does it replace GMP controls or content testing. It is not a branding or artwork system (that is governed under Labeling Control), and it cannot compensate for poor data integrity, weak Document Control, or missing genealogy records. Without aggregation discipline and validated integrations, serial numbers become isolated facts rather than supply‑chain evidence.

2) Legal, System, and Data Integrity Anchors

Serialization operates inside regulated quality systems. Electronic identities and events are records subject to 21 CFR Part 11 and EU Annex 11 expectations, with software validated under CSV and protected by immutable audit trails. Sector rules vary—pharmaceuticals (e.g., US and EU track‑and‑trace regimes), medical devices (UDI, Part 830 plus Part 821 traceability), and food logistics (traceability and GDP). Data structures should follow GS1 identification keys (GTIN, SSCC, GLN) and data carriers (GS1 DataMatrix, GS1‑128), with interoperable event exchange via EPCIS. These anchors ensure that serialized evidence is recognizable, shareable, and defensible.

3) The Evidence Pack for Serialized Identity

A complete serialization dossier connects configuration, execution, and exchange. It captures master data (GTINs, pack hierarchies, GLNs), commissioning and aggregation events with timestamps and operators, print templates and versions, vision‑system pass/fail logs, exception handling (rework, decommission, disaggregation), shipping documents including ASNs, and external acknowledgments (EPCIS receipts). Warehouse records show that only valid, aggregated, and released items were picked and loaded, and genealogy queries can reconstruct any unit’s path from pack to pallet and beyond.

Master data: GTINs, hierarchy rules, GLNs, and effective‑dated label templates.
Line evidence: commissioning logs, camera/OCV results, reject bin reconciliations.
Aggregation trees: unit→case→pallet relationships and edits (split/merge).
Events & exchange: EPCIS events and partner acknowledgments; ASN/SSCC alignment.
WMS controls: status, FEFO, scan history at staging and loading.
Investigations: duplicate serials, unreadables, and rework trails under Deviation/NC with CAPA.

When this pack is governed under Document Control with attributable signatures, serialization becomes an auditable supply‑chain backbone rather than a line‑item project.

4) From Master Data to Shipment—A Standard Path

1) Define & qualify. Author GTINs, pack hierarchies, and label templates; qualify printers/cameras; validate systems.
2) Commission & verify. Generate serials, print at pack, verify with vision, and reconcile rejects.
3) Aggregate & label. Build cases and pallets with verified parent‑child links; apply GS1‑128/SSCC labels.
4) Publish & control. Send EPCIS events and the ASN; block picks for un‑aggregated or un‑acknowledged items.
5) Ship & receive. Scan at dock; partners validate SSCC and contents; exceptions trigger investigation workflows.
6) Maintain & recall. Preserve events and relationships for returns, RMAs, and recall drills.

If any step falters—unclear hierarchy rules, failed camera checks, or missing partner acknowledgments—identity trust erodes and shipments may be blocked or quarantined.

5) Handling Exceptions, Rework & Returns

Exceptions are inevitable and must be designed‑in. Duplicate serial detections require immediate quarantine and root‑cause analysis. Unreadable or misprinted units are decommissioned or destroyed, with camera reject bins reconciled every shift. Rework that opens a case or pallet must disaggregate affected branches of the tree, commission replacements if needed, and re‑aggregate before release. Returns processing should verify serial validity and state (active, decommissioned, or suspect) before any reprocessing or restocking. All flows are governed under Deviation/NC with documented CAPA where systemic causes are found.

6) Contract Packaging, 3PLs & Trading Partner Oversight

Many organizations rely on CMOs, CPOs, and 3PLs to package and ship. Quality Agreements and technical annexes must define master‑data stewardship (GTIN, GLN), serial number ownership, printable templates, event timing (commission, pack, shipping, receipt), the exchange standard (EPCIS), and acceptable latencies. When responsibilities split across organizations, GLNs anchor who did what, where, and when; ASNs and SSCCs tie physical loads to digital records; and partner acknowledgments are treated as release gates for outbound loads.

7) Data Integrity—Proving the Proof

Serialized identities are only as strong as the records beneath them. ALCOA(+) principles apply: events must be attributable to real users and lines, contemporaneous with time‑synchronized clocks, and preserved in their original form with audit trails. E‑signatures bind critical actions (template releases, batch starts, rework approvals) per Part 11. Interfaces that move serials and events between MES, L3 site servers, WMS, and partner hubs must be validated under CSV so that the same identity persists from pack to pallet to partner.

8) Packaging Line Controls & Vision Systems

Pack lines implement 100% print‑and‑verify at speed. Human‑machine interfaces (HMI) lock operators to the correct job, printer, and camera settings; line clearance prevents carryover; vision systems perform OCV/OCR and grade barcodes; and poka‑yoke interlocks eject non‑conformances automatically. Rejects are physically segregated and digitally reconciled. Any change to templates or print rules flows through governed Document Control.

9) Warehouse Execution, Status & Interlocks

In the warehouse, serialized identity is treated as a control, not a label. The WMS prevents allocation of items with broken aggregation or blocked status, enforces FEFO, and requires SSCC scans at staging and Dock Loading. If inventory is re‑palletized, the system records disaggregation and re‑aggregation events and issues a new SSCC before handover. These interlocks mean a truck cannot be loaded with the wrong goods simply because a paper pick ticket said so.

10) Labeling, Standards & Variable Data

Serialization rides on standard identifiers and data carriers. Units often use GS1 DataMatrix encoding GTIN (AI 01), serial (21), lot (10), and expiry (17). Cases use GS1‑128 with GTIN (01), lot (10), expiry (17), and a case serial or content indicator; pallets use an SSCC (00) and optional content summaries. Devices may also require UDI per Part 830. Regardless of sector, Label Verification must validate both data and symbology quality before goods leave the line.

11) EPCIS Events & Interoperability

EPCIS expresses “what, when, where, and why” for serialized movements. Line commissioning is typically captured as ObjectEvents; case/pallet building as AggregationEvents; shipping as Object or TransactionEvents linked to orders or ASNs. Well‑formed EPCIS keeps partners aligned and makes lifecycle queries—“show me all recipients of this lot and serial range”—fast and reliable. Without event discipline, a well‑printed barcode is just ink.

12) Validation Lifecycle—Equipment, Software & Change

Printers, cameras, scanners, and site servers require IQ/OQ/PQ and change control. Software that generates serials, templates, and events is validated under CSV. Template changes, hierarchy edits, or partner‑interface updates run through MOC with impact assessments and controlled deployment to the line. Ongoing monitoring (CPV) tracks read rates, duplicate alerts, and event latencies to keep performance inside control limits.

13) Metrics That Demonstrate Control

First‑Pass Read Rate (FPRR): percent of units passing vision on first attempt.
Aggregation Accuracy: cases/pallets verified without rework.
Duplicate/Collision Rate: rate of serial conflicts per million commissioned.
EPCIS Success & Latency: percent acknowledged within SLA; median seconds from pack to publish.
ASN/SSCC Conformance: shipments where physical contents match digital declarations.
Dock Scan Compliance: percent of pallets scanned and validated at loading.

These indicators convert serialization from a compliance checkbox into a performance system that protects customers and speeds flow.

14) Common Pitfalls & How to Avoid Them

Template drift. Lock artwork and data rules under Document Control; deploy via governed releases.
Clock skew across systems. Time‑sync line devices, L3 servers, WMS, and gateways; use monotonic sequence checks.
Broken aggregation during handling. Require scan events on open, split, and merge; block shipment until trees are intact.
Partner exchange gaps. Treat EPCIS acknowledgments as gates; reconcile ASN, EPCIS, and WMS loads before trailer seal.
Unmanaged rework. Route rework through designed disaggregation/re‑aggregation workflows, not ad‑hoc relabeling.
Label performance issues. Specify substrates/inks and validate durability; monitor real‑world scan grades.

15) What Goes in the Serialization Record

An audit‑ready record identifies the product and configuration (GTIN, pack level), the batch/lot, the serial ranges commissioned, printers/cameras used (ID and status), template IDs and versions, pass/fail counts with reject reconciliations, aggregation trees (unit→case→pallet), EPCIS messages and acknowledgments, ASN/SSCC details, warehouse status and scans at handover, and any associated deviations/CAPA. Approvals are attributable and immutable per Part 11.

16) How This Fits with V5 by SG Systems Global

V5 Identification & Master Data. The V5 platform models GTINs, pack hierarchies, GLNs, and SSCC rules as version‑controlled master data. Label templates (text, AIs, barcodes) live under Document Control, so every printed code can be traced to the exact template and rule set in force at the time of packaging.

V5 Print‑and‑Verify Orchestration. On the line, V5 MES issues jobs with the correct template, serial pool, and device parameters. It connects to printers and vision systems, enforces line clearance, records OCV/OCR/grade results, and reconciles reject bins automatically. Non‑conforming packs are decommissioned; good packs are commissioned and released to aggregation.

V5 Aggregation & Rework Workflows. V5 manages case‑build and palletization in real time, generating GS1‑128 case labels and SSCC pallet labels with scanner confirmation. If a case is opened or a pallet is rebuilt, V5 guides disaggregation/re‑aggregation with full history, preventing “ghost” contents and ensuring that only intact trees can move forward. Designed rework flows integrate with Rework SOPs so fixes are controlled, not improvised.

V5 EPCIS Publisher & Partner Connectivity. V5 natively produces EPCIS events (commission, aggregation, shipping, receipt) and transmits them to trading partners or sponsor hubs. It monitors acknowledgments and treats failures as shipment holds. Where EDI is required, V5 pairs EPCIS with EDI messages and aligns contents with the outbound ASN to keep physical and digital twins synchronized.

V5 WMS, Staging & Handover. The V5 WMS enforces serialization rules on the floor: FEFO on picks, status interlocks that prevent allocation of un‑aggregated items, and mandatory SSCC scans during Outbound Staging & Handover. If the truck load does not match the SSCC and EPCIS declarations, V5 will not generate a compliant handover record.

V5 QMS & Exception Control. Exceptions—duplicate serials, unreadables, partner rejects—spawn records in the V5 QMS as Deviations/NCs with linked CAPA. Because MES, WMS, and QMS share identities, investigators can click from a serial failure to the exact template, device, and operator context.

V5 Analytics, Genealogy & Recall. V5 maintains end‑to‑end genealogy so that a single scan can reveal a unit’s pack history, case/pallet parents, and every ship/receive event. Inventory and shipment dashboards highlight serialization KPIs (FPRR, EPCIS latency, ASN match rate) and power one‑click mock recalls that filter by GTIN, lot, date range, or destination—accelerating Recall Readiness drills and real‑world responses.

Bottom line: V5 turns serialization into a closed‑loop control system—what you print is what you verify, aggregate, publish, ship, and can prove—without spreadsheets, manual reconciliations, or partner surprises.

17) FAQ

Q1. Do we need unique serial numbers on every unit?
In many regulated markets, yes for saleable units. Even where not mandated, unit‑level serialization plus aggregation improves recall speed and anti‑diversion controls.

Q2. Is aggregation mandatory?
Regulations vary, but operationally aggregation is essential. Without it, every case must be opened to verify contents, slowing distribution and increasing risk.

Q3. What happens during rework?
Affected units/cases are disaggregated, non‑conforming serials decommissioned, replacements commissioned, and the tree re‑aggregated before the stock can move.

Q4. How do EPCIS and ASNs relate?
EPCIS communicates serialized events and relationships; the ASN communicates shipment and packaging details for logistics. Together they keep physical and digital views aligned.

Q5. Which barcode should we use?
Follow GS1 guidance: GS1 DataMatrix for unit packs, GS1‑128 for cases, and SSCC labels for pallets. Device UDI adds specific composition and placement rules.

Q6. How do we manage returns?
Verify serial state (active, decommissioned, suspect), confirm aggregation history, and disposition under governed RMA and Reverse Logistics procedures before any re‑stocking.