Product coding (AC 1.2) is how a supply chain keeps the right item moving to the right place. The examiner tests the reasons for coding, the types of system, code structure and validation (check digits), industry-standard examples, and the move from codes into barcodes, QR, order tracking and RFID.
1. Why product codes are used
Using product codes across a supply chain reduces the risk of ordering or delivering the wrong item and supports accuracy, traceability, control and efficiency. The choice of system is each organisation's own decision and must align with operational needs, systems capability and the nature of items managed. Several coding systems often coexist within one organisation, and codes may be designed internally, imposed by customers/suppliers, or adopted from industry standards.
2. Types of coding system (AC 1.2)
- Own product code — aligns with internal software and item variety, giving flexibility and control, but may not be recognised outside the organisation.
- Manufacturer's code — the same code is shared across the chain, reducing interpretation effort and errors and supporting traceability (vital for spare parts), but it can reveal product origins and let customers compare suppliers.
- Customer's code — shared coding simplifies communication, but the customer effectively controls the system; a dominant customer's code can become an informal industry standard.
- Industry-standard code — standardises part numbering across customers and suppliers for consistency and interoperability, though it may not accommodate extra product features.
- Multiple codes — one product may carry several codes (country of origin, production/use-by date, supplier, pack quantity, storage requirement/location, country of use).
3. Code formats and structure
Codes may be numerical, alphabetical, alpha-numeric, random-generated (reduces mis-keying but harder to sort) or sequential (e.g. 1000, 1001, 1002). Structured codes give meaning to parts of the code — product type, material, size, colour, finish, origin, volume or pack quantity — so a similar product can carry a very different code if even one element differs. Organisations frequently create their own SKU systems, which may or may not be structured. The guide stresses that the same SKU number can appear in different suppliers' and buyers' systems yet mean different items (a UK six-pack of cola, an Australian snack food, UK flower seeds), which is exactly why multiple coding systems add value and why an item's full specification must be confirmed before ordering.
4. Check digits and validation (worked illustration)
Many codes embed a check digit for computer-based validation, cutting mis-keying. The guide gives three methods: simple adding-up of digits, multiply-then-add schemes, and modulus checking (e.g. modulus 11), widely used since the 1960s in banking and industry.
Worked example — a modulus-style check (trainer-supplied, illustrative)
For digits 4-3-1, apply weights 3-2-1: (4×3)+(3×2)+(1×1) = 12+6+1 = 19. With a modulus-10 scheme the check value is 10 − (19 mod 10) = 10 − 9 = 1, giving code 431-1. If a clerk mis-keys 4-3-7, the weighted sum changes and the check digit no longer matches — the system rejects it at entry. (Method illustrative; real schemes such as EAN-13 use defined weightings.)
5. Industry-standard examples (AC 1.2)
The study guide names several: ISBN (now 13 digits — prefix, language/region group, publisher, publication number, check digit); the Harmonized System (HS) governed by the World Customs Organization (six-digit codes, countries adding two or four further digits, used for import/export statistics, taxes and quotas); the NATO Stock Number (NSN) 13-digit military code (one product → one description/specification across all NATO operators); IEC battery codes (e.g. AA = LR6); car-bulb numbering (380/382); and the UN Recommendations on the Transport of Dangerous Goods (classifications and code numbers for hazardous substances).
6. Barcodes, QR codes, order tracking and RFID (AC 1.2)
Barcodes convert characters into bars and gaps read by a laser or camera scanner, enabling itemised receipts, remote price updates, real-time stock visibility and automatic reordering. The most widely used is EAN-13 (now within IAN/GTIN, governed by GS1, using a modulus-10 check digit and compatible with the EPCs used in RFID). QR codes are 2-D barcodes holding more data, less error-prone, readable by most smart devices, used for batch, routing, date and returns information.
Order tracking is now an expected feature: internet-based systems integrate order processing, payment and delivery, mostly using barcode scans at hubs and on delivery, with confirmation by handheld device and signature. RFID uses radio tags — passive (activated by a reader) or active (periodically transmitting) — to identify and track items without line-of-sight; applications run from store security and pallet/container tracking to whole-life tyre tracking from manufacture through retreading to disposal. Multiple RFID standards exist, so reader–tag compatibility must be checked before investment. The guide notes a decline in highly structured codes as databases now allocate and link codes instantly — driven by B2B and B2C online growth.