Junilu Lacar wrote:One more thing. You may or may not have done this intentionally but notice how your Patron class is kind of the central hub for your diagram. This tells me that you probably see a Patron is a key entity in your system design. I would argue otherwise. If this is a Library Reservation system, the key entities are more likely to be things like Title, Item, and Reservation. Everything this system does revolves mainly around these classes. Just because a real-world patron is a key user of your system, that doesn't mean the software representation of a patron is central to your system's design.