Source system Analysis - SAP

This is the first data warehouse, I am working which has SAP as its source system. I don't have much knowledge on SAP process flow, tables etc. Have seen couple of screens where users query for some details. Last week for one of the data issues, I was searching online for the "Billing Document" flow. Initially assumed that all Billing documents are Invoices, later the below comments in the SAP discussion clarified the point.

1) What is the difference between billing document and invoice?

Billing document is a general term that includes - sales invoice, debit memo, credit memo and cancellation documents. In layman's term, invoice usually refers to the sales invoice, or what you send to your customer as your company's bill or charges. So, all billing documents are not invoices..But all invoices are billing documents . Usually, Invoice is document indicating to delivery goods and Billing is a receipt of payment

Tables are VBRK & VBRP. For flow, go to transaction VF03, enter document number and hit 'Display Document Flow' button on toolbar VBRK and VBRP holds billing/invoice details.

Also I found that SHKZG field is called return/cancellation flag. When this flag is set, It means that invoiced item is returned to its manufacturer. There are 2 ways of Invoice cancellation, 1) by issuing a Invoice cancellation billing document 2) by setting this return flag set along with Credit memo Billing document.

If I found more, Will post in my next blog.

Happy Learning!