Thanks a lot Yuksel and Donka ..
If the customer wants to use SAP WEB GUI rather than SAP GUI .. still we can implement ABAP single sign on using SAML as the service provider and ADFS as Identity provider over the internet .Pls correct me if my understanding is wrong...
Just came across the below link .If i follow the below link for configuraiton wil the customer will be able to access the system using SAP web gui with single sign on using saml protocol.
Pls correct me if i am worng.