You can analyze slow-moving products by looking at stock movements over time. Here's how to do that:

Steps:

1. Go to: Inventory > Reporting > Warehouse Analysis
2. Group By: Product
3. Add Measures such as:
   • Quantity Done
   • Quantity In / Quantity Out
   • Value
4. Apply Filters:
   • Date Range (e.g., Last 90 days)
   • Location if needed (e.g., internal warehouse only)

What to Look For:

• Products with low or zero Quantity Out over a reasonable period (e.g., 60–90 days).
• Products with high stock levels but low movement — these are typically your slow movers.

Tips:

• Use Pivot View to export data to Excel/CSV for deeper analysis.
• Add custom fields or use Odoo Studio to tag “slow-moving” items if needed.

Odoo v13 Community Edition doesn't have built-in inventory aging or slow-mover reports. So while Warehouse Analysis works, it’s a bit manual and limited.

Alternatives & Enhancements

1. Custom Report (via Studio or Developer Mode):

• Create a custom report or view on stock.quant and stock.move models.
• Calculate:
  • Last outgoing date
  • Days since last movement
  • Average sales per month

2. Excel Export + Analysis:

• Export Warehouse Analysis or Inventory Valuation report.
• In Excel, calculate:
  • Turnover ratio = Quantity Sold / Average Stock
  • Days of inventory = 365 / Turnover ratio

3. Third-Party Modules (Optional in Community):

Some Odoo partners have free or paid modules for:

• Inventory aging
• ABC Analysis
• Dead stock alerts

https://apps.odoo.com/apps/modules/17.0/fsn_analysis_enhanced