For usage within Live-Browse, Snapshot, Audit etc., the Extended Object is the way to go.
You can also use them within Compliance.
From BSA 8.6 you could also run Commands from within a Compliance Rule and evaluate the output within the rules.
This allows not too complex things, but could save you from having to write an EO for every little action.
fyi - local user account information is natively available in bsa...
Say suppose we want to deliver information not included in a standard BMC Bladelogic installation then as Steffan said we should use Extended objects. Please let me if my understanding is correct.
As steffen said you can use extended objects.