The database I'm currently building is pretty complicated to me. So it would be much more complicate if i try to explain so i will try to generalize. The question is at the end of the post.
The table PlanForMakeACar holds information about to build a car and has a relationship to the table "measurementData" which holds created data while the production process.
The table "machine_manufacturing" just holds the information for the group "manufactures" which machines do they have for production.
Is that okay or do i miss something to avoid the loop? My researches showed me the following contribution: Why sould I avoid loops