There's clearly structure you can abstract away; doing so may be convenient, and that convenience may even make it a good idea. I contend, though, that if it d

There's clearly structure you can abstract away; doing so may be convenient, and that convenience may even make it a good idea. I contend, though, that if it does not represent a "piece of knowledge" that you're factoring out then you are dealing with concerns other than "DRY". I do agree that a piece of knowledge may not be a business concept.