Cost Management in 11i

I understand that 11i, you do not create any accounting entries in cost management unlike in R12 where you create WIP/ Receipt and Inventory in Cost Management. 

in 11i inventory for example,  the inventory cost is actually generated in inventory module , is that accurate?.  So,  Cost Management is where you set up the basic cost  such as material  and overhead  but  accounting entries are still generated in Inventory based on flow of activities..

what really cost management in 11i in a nutshell and what does it inventory cost and WIP?