Part of SAP Controlling module is Cost Element Accounting. It is under this area where you maintain directly master data of cost elements. Just to refresh your mind about cost element.
There are two types of cost elements in Controlling, namely; primary and secondary cost element. Primary cost elements are use to transfer P&L account postings in Financial (FI) to Controlling (CO). It is a requirement that all P&L accounts should have a primary cost elements; otherwise, transactions can not be posted involving P&L accounts in FI. On the other hand, secondary cost elements are use only for allocation and assessment purposes as period-end process.