This activity is used to select the base for cost/revenue element. Any code part other than code parts assigned
to functions can be selected as a base for cost/revenue element. It is not possible to change the selected code
part as long as connections between the code part value and follow-up elements exist in the Cost/Revenue
Element per Code Part Value page.
As a result of this activity, cost/revenue elements can be connected to code part values of the selected code part in the Cost/Revenue Element per Code Part Value page.