On the check table STG_VENDOR_SAP4 (in the bottom left side), I have set the data rules action to Report. In this way, you will have a record for each bad check in error logging table. To know more : OWB - How to implement and manage data rule in a mapping for a table ?

I use a cross join to generate the number of rows that I must have in the fact table

To avoid the warning VLD-1504 join condition expression is not specified, I have specified as condition : NULL IS NULL (of 1=1)