drawing UML Use case diagram

Question

I am going to draw uml use case diagram for follow scenario :

In the university to set up a new coffee management system. These are the (informal) requirements:

1. A coffee machine dispenses coffee at the press of a button.
2. There are different coffee flavors (espresso, cappuccino, or latte macchiato) with different
prices.
3. Every user has an account on the coffee management system.
4. Every user logs on to the system using some identification (a password or picture).
5. Users choose the coffees they had (or will have) and mark them as “dispensed”.
6. The price for the coffee is automatically deducted from their account.
7. A special user (the “administrator”) can recharge user’s accounts.

How can I create a use case for the above scenario including alternatives and exceptions.

I tried to draw use case diagrams, please if someone can check is it correct or not. Thanks in advance.

Answer 1

I had here a dialogue with one UML starter over another system. I think, the discussion could be useful for you.

I would:

• change type password to login. Throw off verify user.
• Add create login, set password, change password, delete login - more use cases for Admin.
• Join login and all those into Account management rectangle = a subsystem.
• Nowhere it is said that the user should be student. Don't limit entities without reasons.
• Add Add/Remove/Edit Sorts and Set/Edit Prices use cases to Admin. Join them into Assortiment subsystem.
• Add View Assortiment for the User.
• Put generalization arrow from admin to user. Admin can use the system, too, and he needs login.
• Add look account state to the user

• Where do you have this "mark them as “dispensed”" and how do you imagine it?

• Use some tool for editing. To redraw the diagram at every edition takes much time. (You could take free variant of VP-UML, it is not ideal, but practicing this you are learning to one of the three widely used proprietary tools)