Do not cost indicator in Material Master - Impact in CO-PA

Hi,

I wanted to freeze the SFG cost while valuating FG & hence I activated "do not Cost" in SFG material master. Post that when I run cost estimate for FG & try to view the cost component break-up, system does not bifurcate material cost into Raw Material, Packing material etc. but shows under cost component group "SFG". As a result, even CO-PA cost component breakup shown total material cost as SFG. The same is not the case if SFG is not ticked as "Do not Cost" indicator. Meaning: CO-PA cost component breakup shows "Raw Material", "Packing Material" etc.

Can anybody throw some light on this?