Hi Maren,
BAdi CRM_ORDER_STATUS is a filter dependent BAdi and its trigger is dependent on the filter that has been set.
Before_save method lets you to perform validation before the status is being set and depends on your logic you can control the further status to set or prevent. Similarly After_save method lets you to perform validations after the specific status has been set.
Coming back to your question, you must need to see the filter value of your implementation. This could be the reason why you cant see your implementation not getting triggered while debugging. It should trigger once filter value is matched with the status of your service order.
For your requirement if i understand correctly you needed service order status not to be changed before all service item status is 'closed'. You should create an implementation with the filter value ( combination of user status & status profile ). Here in before_save method you can write your logic to check the header status if not 'Closed' raise exception 'NOT_ALLOWED'.
Regards,
Atul
