Sales Analysis - Error

Hi

I assigned the role 'com.sap.pct.best.EC_Sales' and was able to see a menu 'Sales Analysis'. I have created the System alias as 'SAP_BW_BP'. When i click on the link it gives an Error.

Portal Runtime Error

An exception occurred while processing a request for :

iView : N/A

Component Name : N/A

Unable to lookup System 'SAP_BW_BP'. Please check the system object and the alias..

See the details for the exception ID in the log file

com.sap.portal.appintegrator.sap.BWReport::BWReport/RoadRunnerSSOLayer

i have a few questions:

1) What is this role for ?

2) Why could this error have occured when i have my system alias in place ?

Murali.