OIM - System Administrator initial login time is greater than usual

When Sys Admin tries to login to OIM basically executes tree queries to display the counts for his pending approvals , open tasks etc to avoid this you can do following

From Design console go to System Configuration
search for "XL.WebAdminHome.CounterDisplay.Type"
change values from "DayLimit" to "CheckLink"

if this property is not available in design console then do following.

See Oracle Metalink Doc 741590.1 for all the details, In short do following:

Edit the WEB-INF/classes/xlWebAdmin.properties
and change the webadminhome.message.skipPendingApprovalsOpenTasksCounter to true, and the run the patch_websphere.sh script to build and deploy the new war.