Hi Leandro
Since you are observing performance issues on both CO01 and MD04, this is probably something related to the database.
The most common cause for this issue is the size of the database database table RESB. Try to update the statistics for this table and to archive old production orders to reduce the size of the table.
Take a look on the documentHow to analyze transaction MD04 in debug where I explain how to debug MD04. There is a form to select data from each one of the tables and if you check them in debug, you will be able to find which specific one is taking more time.
BR
Cetano