SKU Architecture for a Lamp Programme: Naming, Variants and the Cost of a Messy Catalogue

SKU architecture sounds like a systems topic and behaves like a margin topic. Every avoidable variant costs a slot in the warehouse, a line on a purchase order, a page in the catalogue and a decision at the pick face. Lamps generate variants faster than most categories because colour is a selling feature, pack size is a channel decision, and finishes multiply quietly: a body colour, a shade colour and a metal trim can produce combinations nobody intended to sell. The discipline is to decide the structure before the assortment grows, not after. Our line sheet article covers how to read a supplier's catalogue; this one covers how to build your own.

Sprawl starts with colour

The first variant is always defensible. A customer asks for black, the supplier can make black, and a new SKU is born. Then brass, then white, then a shade change on the black one because the fabric ran out. Within two seasons a single lamp shape has nine numbers, four of which sell, three of which are discontinued but still in the system, and two of which are the same product under different codes inherited from a previous buyer.

The cost is not the extra numbers themselves. It is the decisions they force: which one goes on the shelf, which one the sales team quotes, which one the warehouse picks when a customer orders by description, and which one gets reordered when the sell-through report shows a colour selling out.

A structure that survives replenishment

The most durable structure separates three things that buyers habitually merge: the base model, the variant, and the pack. The base model is the shape and the specification — the thing that carries the safety listing and the replacement-part identity. The variant is the finish combination. The pack is how many units ship in a carton and how they are merchandised.

Separating them lets you discontinue a finish without retiring a model, change a pack size without rewriting the product record, and report sell-through by shape rather than by colour. It also makes the supplier conversation cleaner, because a base model maps to a factory model and a variant maps to a work order.

Naming: what the number should tell the picker

A SKU is read by three audiences: the buyer placing an order, the picker filling it, and the system matching it to a barcode. The number has to be short enough to say aloud and structured enough that a mistake is visible. A useful pattern is model, variant, pack, in that order, with fixed widths so that a truncated code is obviously wrong.

Two rules save most of the pain. Never reuse a retired code for a new product, because history becomes unreadable. And never let two codes describe the same physical item, even temporarily, because that is how duplicate stock appears in a warehouse that is certain it has none. Our UPC and barcode article covers the retail-facing side of the same identity problem.

Case packs are a channel decision

A lamp sold in a store and the same lamp sold online often need different case packs, and that single decision multiplies the catalogue. A two-pack merchandises well on a shelf and ships cheaply to a consumer; a single unit is what a replacement buyer wants; a six-pack is what a small dealer orders. Each is a legitimate SKU and each is a separate carton, barcode and line on the purchase order.

The discipline is to allow pack variants only where the channel genuinely requires them, and to keep the base model identical across packs. When pack size becomes a way to differentiate products rather than to serve channels, the catalogue stops describing the range and starts describing the warehouse.

What a messy catalogue costs, line by line

The costs are small individually and add up quickly. The table below is the arithmetic worth doing before the next assortment review.

Migrating without breaking history

If the catalogue is already messy, the fix is a mapping rather than a purge. Build a crosswalk from old code to new code, keep the old codes searchable for at least a full selling cycle, and move inventory in one controlled step rather than letting both codes coexist indefinitely. Reuse nothing; retire visibly.

A small range makes this easy, which is one argument for starting narrow. Anrotix keeps nine SKUs — six floor lamps and three table lamps — in a defined set of finishes, 120V with E26 bases and US plugs, stocked in the United States and orderable from ten units with mixed SKUs. If you are building an assortment and want the SKU list in a form you can paste into a system, ask help@anrotix.cn and we will send it with the variant and pack fields separated.

Frequently asked questions

Should every colour be its own SKU?

Only where the colour is separately stocked and separately sellable. If a finish is made to order or is a trim detail on the same body, it can often live as an attribute rather than a SKU. The test is whether you would ever hold inventory of that variant on its own.

How do pack sizes fit into a SKU structure?

As a separate field rather than as part of the model identity. Keeping base model, variant and pack distinct lets you change a case pack without retiring the product, and lets sell-through reporting roll up to the shape rather than fragment across cartons.

Can old SKU codes be reused once a product is discontinued?

No. Reuse makes sales history unreadable and creates a risk that a system matches an old order to a new item. Retire the code visibly and keep it searchable for a full cycle so that customer service and forecasting can still read the past.