Inventory Management with Product Variants

The problem with variants in traditional systems

In Excel or basic ERPs, each size/color/material combination is a separate line in the product catalog. For a product with 3 colors × 5 sizes, you have 15 lines to maintain separately — leading to pricing inconsistencies, copy-paste descriptions, and a spreadsheet that grows uncontrollably.

The real solution: a parent product with variant attributes. The "Classic" T-shirt is one product. Its attributes (color, size) automatically generate its variants. The base price is shared; variant-specific prices are optional.

The 4 most common variant types

1. Attribute variants (fashion, retail)

Size (XS→XXL), color, material, style. Each combination is a distinct SKU with its own barcode, stock level, and optional price.

2. Serial numbers (electronics, equipment)

Each unit has a unique number. The ERP tracks which serial number was sold to which customer — essential for warranty and after-sales service.

3. Lots (food, pharmaceutical)

Products are received and sold by batch with an expiry date. The FIFO rule (First In, First Out) is applied automatically.

4. Multiple units of measure (trading)

Purchased by pallet (240 units), sold by carton (12 units) or individually. Conversions are automatic in purchase orders and invoices.

Best practices for structuring your catalog

• Standardize your attributes before importing: decide accepted values for "Color" (White, Black, Red — not "white", "WHITE", "W.")
• Use logical product codes: TSHIRT-M-BLK-001 is readable; A00123 is not
• Set minimum stock alerts per variant, not just at the parent level
• Link each variant to a supplier to automate reorder purchase orders

How to migrate your current catalog

• Step 1: Identify product "families" (e.g., Classic T-shirt, Slim Pants...)
• Step 2: Prepare a CSV with columns: Parent product, Attribute1, Value1, Attribute2, Value2, SKU, Stock, Price
• Step 3: One-time import — the ERP automatically creates the parent product and all variants