SAP has different solutions for Inventory management.I have created a screen cast for explaining the different SAP inventory management solutions.This screen cast discusses the various Inventory management solutions available in SAP and compares their key features available . Most importantly it compares between all the inventory management solutions viz. SAP IM, SAP WM, SAP Lean WM, SAP WM and SAP eWM solutions .This is a generic comparison and will help to understand each solutions strengths and weaknesses.As each business is different more in depth study will be required to finally decide upon the best solution.
A more detailed comparision between SAP eWM and SAP WM is presented in another article.
You can find in my article sap wm vs ewm