From my experience in working in the industry, the DHF i believe should be a living document along with the DMR. I can understand that the DHF is a history of the initial design history, SOP’s, and design control documents such as DID, DSD and PDF along with the Validation and Verification protocols and reports. In the company that I work for currently, this document is a living one in the sense that the document can be edited and made changes with a Change Order Request; however ensuring that the changes does not change the general concept of the product, otherwise it would be considered a new product to the FDA. As mentioned prior by the previous students, the DHF is a snapshot of what the product stands currently. The DMR on the other hand is a record of all design drawings, processes, etc. This document will reference all the changes done in the DHF as well.