The production code is the budget line from the estimate. The expense item is a sub-item in Setup and Operation that is linked to a production code. It is used to accrue and follow up the cost month by month.
How they fit together
Production code: Found in Prod. Codes and has a budget, final forecast and posted cost.
Expense item: Found in Setup and Operation and shows how the cost on the production code is distributed over time.
A production code can have one or more expense items.
If you delete
If you delete an expense item in Setup and Operation, the production code remains.
If you delete the production code, you should also delete the expense item.
In other words, deleting one does not automatically delete the other.
Good to know
The table in Setup and Operation can be grouped by both production code and expense item.