Automate Inventory Forecasting & Reorders with n8n

Transform your inventory management from reactive guesswork into proactive, AI-powered forecasting with this comprehensive n8n workflow that automatically calculates stock levels, predicts stockouts, and generates purchase orders before you run out.

What this workflow does

This intelligent automation fetches your sales history and current inventory data from Google Sheets in parallel, then performs sophisticated calculations to determine days of stock remaining, average daily sales velocity, and projected stockout dates for every product in your catalog. An integrated GPT-4o mini AI agent analyzes this inventory snapshot and generates a structured forecast report covering critical alerts, reorder priorities, demand trends, and supply chain risk flags. The workflow automatically routes urgent stock alerts to your Slack channel for immediate visibility, creates purchase orders for all flagged items, and logs the complete forecast analysis back to Google Sheets for historical tracking.

Use cases

• E-commerce businesses managing multiple SKUs across online stores
• SaaS operators tracking subscription-based inventory or digital products
• Retail companies needing automated reorder point calculations
• Supply chain managers requiring daily inventory velocity analysis
• Operations teams wanting proactive stockout prevention alerts
• Inventory planners seeking AI-powered demand trend insights

Technical details

Built with essential n8n nodes including if conditions for logic routing, set nodes for data configuration, code nodes for custom calculations, merge functionality for parallel data processing, and Slack integration for real-time notifications. The workflow connects seamlessly with Google Sheets OAuth2 for secure data access and OpenAI API for intelligent forecast analysis.

Setup requires connecting your Google Sheets OAuth2 credentials, adding your spreadsheet ID to the forecast configuration, and ensuring your sheet contains Sales_History, Current_Inventory, and Forcast_Analysis tabs. Simply add your OpenAI API key, connect your Slack workspace, configure the alert channel, and you're ready to automate your entire inventory forecasting process in under 10 minutes.