Attached is one approach. I've added the following:
Project::Locator = PartNumbers_Increment::Locator
17-22 (including comments)
This allows a user to:
- Add sizes in any order
- Increment the number for the next product of the same project
- Return to the original product to add more.
I don't know if this schema works with your intended SKU convention. It does, however, keep the SKUs unique.
As an aside, you may be interested in a series of inventory articles I have at FileMaker Inventory Resources. The most recent article is on Variants, which is what you have here. There is also a demo file that's open and ready to be reversed engineered. And I will have a supporting video on my YouTube channel shortly.
sample_NLDv1.fmp12.zip 125.5 K