Back Orders for ERP: data model references ?

Question

My question is: do you know of any real good reference (book, web) for ERP database design ?

I have built an ERP using Sql Server as a back-end. There are different types of Client documents (there are also Supplier Docs):

1. Order -- impact: Back-Orders (BO)
2. Delivery Note (also used for returns, with negative quantity) --impact: BO, Stock
3. Invoice --impact: accounting only
4. Credit Note --impact: accounting, BO

BO tracking is very complex, and involves tracking links between different documents: imagine a returning customer that has ordered several times 10 units of reference X: which delivery fills which order ? If there is a credit note for 5 units of reference X, does it have an impact on BO ? For which order ? (these are just examples)

Answer 1

The Data Model Resource Book.