Trying to develop a better understanding of UML diagram relationships

Question

This is my very first UML diagram for a Student Record System I have created. I've been reading documentation on the types of relationships such as dependency, Association and Aggregation. Any opinions?

larger

Answer 1

Here are some, of the top of my head:

1. Try to arrange it like a tree with dependency arrows going top to bottom. It makes it more readable and allows you to see where improvements can be made.

2. I think you have mixed up arrow direction. If class A makes calls to class B then class A is dependent on class B and arrow should be pointing from A to B.

3. If any class is going to keep an instance of another class then you need to use solid lines to indicate that. e.g. Class A has an instance of class B then use a solid line with arrow from A to B.

Answer 2

If your relationships mean that a class references another class, typically solid lines are used. Dotted-lines indicate a weaker dependency.

If you are using UML as part of documentation, including only the classes/methods of interest makes UML much more readable.