Product Traceability: Batch and Serial Tracking in Production

What traceability means

Traceability is the ability to answer two questions within minutes:

• forward: which finished product lots a specific raw material lot went into, and which customers received them;
• backward: which raw material lots, line, shift and operator produced a specific item.

Tracking works at two levels. Lot (batch) tracking assigns one number to a group of units made under the same conditions: food, chemicals, building materials. Serial tracking gives each unit a unique number: appliances, equipment, expensive components. They are often combined: a product has a serial number, while its components carry lot numbers.

Lot genealogy: from raw materials to shipment

The chain is built from "input → output" links at every step:

1. Receiving. Each delivery gets an internal lot number, linked to the supplier's lot number, date, certificates and incoming inspection results.
2. Production. The work order records which raw material lots were consumed and in what quantity, and which product lot was produced. Semi-finished goods get their own lot numbers too.
3. Packing. Units, cases and pallets are linked by nesting: pallet → cases → units.
4. Warehouse and shipping. A pallet or case is scanned at dispatch, and its lot numbers go onto the sales document for a specific customer.

If even one link is recorded from memory or at the end of the shift, the chain breaks, and a problem forces you to recall more product than necessary.

Labeling and scanning points

Reliable records require machine-readable labels:

The minimum set of scanning points: receiving, issuing materials to production, production output, packing or aggregation, shipping. The closer the record is to the physical action, the more accurate the data. A handheld terminal or a fixed scanner on the line is more reliable than typing numbers by hand.

Use GS1 standards where partners require them: large retail chains and export buyers often expect the GTIN, lot number and expiry date in a standard format.

Recall scenario

When a defect is found, the steps are:

1. Identify the problem lot — raw material or finished product.
2. Trace forward to get every affected finished product lot.
3. Find what is still in stock (block it) and what was shipped (list of customers and documents).
4. Notify customers and arrange returns.
5. Trace backward to find the cause: supplier, line, shift, equipment.

Without traceability, step 2 usually means recalling everything produced over a period. With it, only the lots actually affected. Run a mock recall regularly: pick a random lot and measure how long it takes to produce a complete report.

Which systems store the data

• ERP — lots at receiving, in stock and in sales; often enough for simple production.
• MES — detailed shop-floor data: line, shift, process parameters, operator, quality control.
• WMS — location-based storage, packaging aggregation, lot picking by FEFO or FIFO.
• A dedicated traceability system or module when you need complex genealogy or data exchange with external systems.

The key requirement is a single lot number across all systems and integration between them, so the report is generated automatically rather than stitched together from three exports.

Common mistakes

• Consuming materials "for the whole shift" instead of against a specific product lot.
• Printing labels in advance and sticking them on the wrong product.
• Keeping lot numbers only in a paper log.
• Not linking cases and pallets to units, which loses the connection to the customer at shipping.