“Is possible to integrate a SAP module called “project system” with Project Portfolio Server and Project Server ? “
Yes, it´s possible to integrate SAP with Project Server.
You can see:
2. Latest version of the SDK
3. Duet for Microsoft Office and SAP: http://technet.microsoft.com/en-us/office/bb267348.aspx
The connection with SAP can be realized, in addition, with others connectors of SAP, for example:
1. Bussiness Connector that it uses BAPIS of SAP standard.
2. SAP XI: Communication by means of asynchronous calls “RFC” to modules of function of SAP (PS, HR, CO,…)
3. Connector PSLink. http://www.TheProjectGroup.de