Start the transaction using the menu path or transaction code KA06

Double-click 

Enter

1. the code of the cost element to be created
2. the validity date (01.01.YYYY)
3. a reference when applicable. 

Click or 

in the tab "Basic data" 

Enter: 

1. the name and description of the new cost element

2. The cost element category

   Rules - Cost element Category

When applicable - in the tab "Indicators"

1. Tick "Record qty"
2. Enter a "unit of Measure 

save 

A message displays that the cost element is created