These PK/Fk pairs are surrogate keys not the natural keys from OLTP. They should be built during initial OLAP load and maintained in the subsequent ETL process.
Maybe I should have been clearer from my earlier entries that these are the FKs I'm using. The former PKs may be unique indexed, but all the dimension data is turned into a surrogate key integer, even if the original PK was an integer. I would not advocate trying to maintain the OLTP PK/FK relationship.