Extends and include use cases

Question

I've a doubt about use cases, i will explain the case first and then i will make my question and what i'm doing because i wanna learn how to do it right

Soda Machine::

• The machine manage 5 types of soda (A, B, C, D and F)
• The user have to add the necesary moneys to pay the soda and identify the soda that he wants
• The machine admit 5 types of moneys ($5, $10, $50, $100 and $500)
• When the amount added by the user is higher than the value of the soda, it will return the change in the same types of money
• When the machine dont have the soda that the user wants, it will show a message
• Also, it will show a message when the amount is insufficient
• Can happen that the user add more moneys that the soda required, it means that for example the soda cost $100, and I add $100 and $50. In that case the machine will return the excess of moneys or give the change of that money

My doubt is in the case of the types of soda and the types of moneys, because i have the use case "add moneys" and i dont know if i have to extends the use cases of moneys ($5, $10 .. etc) and the same things for the use case "select soda". I have this:

Answer 1

Uses Cases expresses high level usage between your system (i.e. the soda machine) and users. So in your context I would suppressed all unnecessary UCs like "Check Amount", "Give Soda", "Amount Insufficient", etc. which are usage of your system. And I would also suppressed too much detailled UCs as "A soda", "B Soda", "$5 Money", etc. In fact cf my proposal below.

Hoping It helps, Regards, EBR.

By the way UML has a precise graphical representation so please use it, your diagrams would be easier to understand. I personally use Modelio but a lot of other tools (open source as well) exist.

Answer 2

In addition to what @Red Beard said, the association type that you are most probably looking for is the UML generalization. However, applying it will only make proper sense when you adhere to the UML notation and after getting rid of the clutter. :)