Hi Silviu,
what is your scenario? Which object do you want to track?
For PO a standard Visibility Process is available. PCM10_ITEM in your ERP and EM system in the EM customizing.
If you have access to the Service Marketplace
http://service.sap.com/scm
> SAP SCM in Detail > Event Management
You will find a config guide and a scenario description.
Best regards,
Steffen