I have seen this go both ways in different implementaions. In a hierarchy where there are let's say 6 levels the bottom level is the ID (Example ProductID), but there is a product name that is unique. I tend to think that the ID does not need to be in the hierarchy if the product name is the "human" identifier.
Is it safe to just take it out of the hierarchy?
Update: To be clear - the Product Dimension has ProdID and ProdName on each record. The join to the fact table is on ProdID. The hierarchy had both ProdID and ProdName with ProdID as the lowest level. Can I not just remove ProdID from the hierarchy?
Build the hierarchy based on the IDs and change the "NameColumn" property of the attribute to the Name, so you can see the user friendly name but everything is being calculated by the ID