A categorisation is a hierarchical classification of products. Below are some guidelines to define your categories.

Objectives

• Maximise success rate to find items (90%+)
• Find items in 3-4 clicks
• Inspire browsing by exposing intuitive entries

User requirements

• Users need to be able to understand and physically see "all at once"
• Users shouldn't be guessing where the item is

Tips for structure

• Lowest level categories should be interchangeable, homogeneous groups of products (substitutes)
• Not more than 7 top level categories, maximum 2-3 levels deep, per level maximum 7 choices
• Categories should be highly functional ("by type"), and not include attributes like "brand", "size" etc.
• Focus on high sales categories, expose them prominently
• Limit double product occurrences
• Accessories: position as orphan category, close to the source categories

Tips for naming

• Naming should focus on most important categories
• Avoid too much compounded naming ("Snacks & drinks")
• Use customer speak, not internal speak!