Originally Posted by
keviny04
A few issues that I see:
1. What are the relationships of systems, equipment, and parts? Is a part a "subset" of an equipment? Is an equipment a subset of a system? Any time you have something that is a subset of something, you are looking at a one-to-many relationships.
2. You said a part can have a different part number. How many different part numbers can a part have? Are you sure it is always "a" (i.e. only one) different p/n? This info affects your table design. If you are sure it is always "a" different p/n, i.e. a part can have at most two p/n's, then you just can add a field called "alternate_part_num" to your parts table. If a part can have multiple p/n's, that means p/n's are a subset of a part, so you need, again, one-to-many relationship.
3. You mentioned a part has a serial num, and an equipment can also have a serial num? Are those two different types of serial nums? If so, you need to design your tables accordingly.