AI glossary · Basic · Classic ML, recsys & search · Logistics & supply chain · Retail
Demand forecasting
Demand forecasting is estimating in advance which products will sell, when, where and in what quantities, based on past sales records and information such as weather, events and prices.
About this term
- Level
- Basic · Technical terms you often meet in AI news
- Category
- Industry AI
- Industries
- Logistics & supply chain, Retail
- Added
- 2026-10-10
How it works
First, past sales volumes are organized by product and store in time order. Information that affects demand, such as day of the week, season, holidays, discount promotions, price changes and weather, is attached to them. The model learns these relationships using time series forecasting techniques, gradient boosting or deep learning models, and outputs sales volumes for the next day, week or month. A good system reports not just a single number but also the uncertainty, such as 'it is likely to fall within this range'. As actual sales come in, forecasts are compared against them and continually corrected.
The demand forecasting loop
Improving forecast accuracy
- 1Collect data
- 2Train the model
- 3Forecast sales
- 4Compare with actual sales
- 1. Collect data Sales records, weather, events, prices
- 2. Train the model Learn relationships that affect demand
- 3. Forecast sales Including range and uncertainty
- 4. Compare with actual sales Check errors and correct
Why it matters
In logistics and retail, too much inventory increases storage costs and waste, and too little causes stockouts that lose sales and customers. Demand forecasting is the starting point for almost every operational decision, such as order quantities, warehouse inventory placement, and staff and vehicle allocation. Especially for products with short shelf lives, such as fresh food, forecast accuracy translates directly into the amount thrown away. The longer the supply chain, the more small forecast errors at the front grow further down the line, so accurate forecasts are even more valuable.
Things to know
Sales records from days when a product was out of stock show 'the amount sold up to available stock', not 'actual demand', so training on them as-is leads to underestimating demand. New products have no past records, so data from similar products must be borrowed. During periods when consumer habits change suddenly, models can quickly go off track due to data drift, so ongoing monitoring is needed. Also, rather than feeding forecast results directly into automatic ordering, many setups include a step where people make adjustments so that information only on-site staff know, such as promotion plans, can be reflected.
Example
A large supermarket chain forecasts next week's sales by store and product to set distribution center order quantities and store shelf quantities. For example, when hot weather is forecast for the weekend, the model raises demand estimates for ice cream and bottled water, and delivery vehicle scheduling and warehouse inventory placement are adjusted in advance to match. E-commerce companies use the same forecasts to decide which products to move ahead of time to distribution centers close to customers.