LIS - S001 How can I populate Cost of incoming sales & Cost of Sales??

Hi dear LIS gurus:

For some reasons, key figures in S001 like 'Invoiced Sales: Cost' & 'Orders: Cost' contains 0 are not populated, can one of you guys tell me what do I need to do to get those fields populated? Or can you provide me with documentation as how and what to do in order to populate them??

Thanks!!

David