This document introduces the 3F model for container inventory management (CIM). It summarizes existing CIM strategies and issues, then proposes the 3F model to help carriers minimize empty container costs. The 3F model comprises six strategies (reduce import/export freight, service agreements, synchronized budget, agile inventory, export priority) rooted in three dimensions: freight, forecasting, and flexibility. It aims to establish standard CIM practices and help carriers continuously improve beyond traditional repositioning approaches.