How can I improve this normalization to 3NF/How do you self-check normalization?

Question

this is NOT homework, I'm just trying to improve my normalization skills. The first part is the functional dependencies i've identified and the second is what I believe the appropriate 3NF normalization would look like.

Part numbers (but not Type) uniquely identify parts. Manufacturer names uniquely identify Manufacturers. The Unit Cost of an item is unique to the Manufacturer but not necessarily the part itself. The Part Costs are in reference to how much the Manufacturer sold me the part.

Any additional tips on normalization or explanations relating to this one would be really helpful. Intuitively, this seems correct to me and it makes sense to have all of the manufacturer information in one database. Thank you!

Answer 1

For a better understanding of NF rules, try to query your scheme, and find the issues. Try to insert/update/delete/read. All insert/update/delete should be executed on a single table. To read, you may need to Join. I'll try to give you some advice referred to your design:

1. Practically, we are using generated Identifier as a primary key. This will automatically solve 2NF.
2. ManufactorName doesn't belong to pricing. I don't know which field did you defined as an ID, but anyway, ManufactorName should be part of Manufacturing. Otherwise, How would you update ManufactorName?
3. I guess PartCost dependent on PartNo. Is there any reason to separate PartCost from PartNo?