Thanks for the quick reply.

There are a few elements at the invoice number level that are repeating in the FactRetailSales table (InvoiceNumber, WorkOrderNumber, InvoiceDate and WorkOrderDate. I'm fine with flattening them all out to maintain the Star formation.

My main concern is that there is going to be quite a bit of analysis at the invoice level.

I am designing this DW for a tire and car service retailer. The executives will want to know when a customer came in for a tire, did they also get services (and all possible combinations). We will want to do a lot of customer profiling across the invoice.

I'm using SQL Server 2012 BI tools, I'm only worried I'm going to make my life more difficult when I start working on the cube design.