Hi Praveen,
the below link has a lot of information on these steps, the ID is the important thing. you can also look at the aggregate tab to see how long is taken in each infoprovider. For further analysis I often use st05 to trace the SQL and then I can see the most expensive statements and view the execution plan.
http://help.sap.com/saphelp_erp60_sp/helpdata/en/45/f0488a1aa03115e10000000a1553f7/content.htm
st05