Ecommerce inventory management versus demand planning software: what is the difference?

Inventory management software tracks current inventory and its movements across channels and locations. Demand planning software forecasts future demand and turns it into replenishment decisions: how much to hold, when to reorder, and what buffer protects a given service level. The first tells you what you have, the second tells you what you will need. Many tools do the first well and the second barely, which is why brands often run a system of record for execution and a dedicated planning layer for forecasting and cash control.