AI Inventory Forecasting n8n Workflow: ERP + Postgres

AI Inventory Forecasting in n8n: ERP + PostgreSQL Purchase Orders

This n8n workflow automatically monitors warehouse inventory and sales velocity, uses AI forecasting to predict demand, and generates purchase orders—then logs every transaction into your ERP and PostgreSQL database to help prevent stockouts or overstocking.

What this workflow does

• Runs on a schedule: The workflow checks inventory and sales data every 6 hours (adjustable for higher/lower frequency).
• Fetches live inventory and sales trends: It retrieves current warehouse stock levels from a warehouse API endpoint and pulls sales velocity signals.
• Forecasts demand with AI: Using OpenAI GPT, it predicts future demand based on sales velocity and inventory/stock trends.
• Creates auto purchase orders: When demand indicates restocking is needed, it generates purchase orders and prepares them to be sent to suppliers.
• Integrates with ERP: Completed purchase orders are logged into ERP systems such as SAP, Oracle, or NetSuite.
• Logs details to a SQL database: Purchase order information and forecast confidence data are saved into PostgreSQL (or other SQL databases like MySQL, where applicable).
• Sends email notifications: Relevant teams are notified when purchase orders are successfully created and logged.
• Modular configuration: Each node includes setup guidance and credential/config notes.

Use cases

• Restocking consumables by predicting demand from recent sales velocity and current on-hand inventory.
• Reducing manual purchasing by automatically generating supplier purchase orders on schedule.
• Ensuring audit-ready reporting by recording forecasts and purchase orders in ERP + PostgreSQL.

Technical details

• n8n nodes/stack: code, filter, PostgreSQL (SQL logging), email send, sticky note, HTTP request
• AI: OpenAI GPT for demand forecasting
• ERP support: SAP, Oracle, NetSuite
• Core logic: scheduled trigger → HTTP fetch → AI forecast → generate purchase order → ERP + database logging → email notifications