Today my database has the tables in this first image. The problem is that now I need to do stock control and other products will be added too.
To support many types of products, first I designed the tables in the next image (design 1). This will be a solution to generic products that don't have any kind of serial number to differentiate they.
After doing some research I found the solution in the next image (design 2). This supports generic and the specific products (like SIM cards and devices). I think that the complexity will increase greatly this way. Also there is a problem that I have FKs in simcards and devices. One great thing about this solution is that will support future products with specific data.
What is the best approach to solve this problem?