To repeat a comment that, I believe, I made to an earlier thread of yours, You really have two different sub systems here to your database project. One is a "specifications" system that documents how each product is assembled from it's component parts, assemblies and sub asemblies. Another is your production management subsystem where you schedule products for production.
You should not duplicate the specification data just to set up a production run. Instead, your records should reference the same set of BOM (Bill of Materials) records that document how the product is produced by linking to this data via a ProductID. No record duplication should be done here. Instead, you create a new blank record and select the needed value in a foreign key field to link it to your product record and from there, to the BOM records for that product that describes how one unit of product should be manufactured.
Hi Phil.. I think you're right. I duplicated my thought process.. and didn't realize I had asked the same general question in another thread. I'll go back and re-read your original reply.
but thanks for the quick response. :)
so re-reading.. again... (sorry).. are you suggesting one primary system and two sub systems?. The primary "Inventory, Sales and Purchasing", and the two sub systems... "Specifications" and the other "Production Management"? They still can relate to one another but essentially function independently from each other?
Is it possible that you could illustrate an example of the ERD you describe above?