Product cost collector & MFBF

1) Can anyone shed some light on how to setup product cost collectors in REM environment? & how to maintain them?

Also, how to process the preliminary costing for product cost collector? Why is it done and how often?

2) In MFBF transaction, when we post scrap, system post the scrap on the BOM components and not on the parent material?

E.g.: I have a finished good ABC, having BOM components 1,2,3. When i post the scrap for 100 units of ABC, system scraps the components 1,2,3 as per the BOM. I dont see any Scrap posting for ABC for 100 units. If i want to determine, how much finished goods were scraped, where do i get the information?

Thank you guys..