Assortment planning in retail determines which products you sell, where you sell them, and how well your inventory performs. This guide explains how retailers balance product variety, demand, and profitability through structured assortment strategies. It covers key components such as SKU selection, localisation, and seasonality, alongside a step-by-step planning process. You will also learn how assortment decisions connect to forecasting and replenishment, and how modern software improves accuracy and efficiency. The result is a clearer approach to reducing excess stock, avoiding stockouts, and driving stronger retail performance.