UML用例图 - 抽奖系统

Question

In this use case diagram, I'm trying to show how the raffle admin can view the updated raffle list after a customer has entered the raffle. Once the customer has entered the raffle, the system will verify and check for duplicates and if there are no duplicates, the raffle list will be updated.

The following image is my attempt on the scenario however, I'm not sure if its correct. Can you please advise me?

edit: I have several questions:

1) In the event where I use the raffle system itself to verify the raffle entry, I would not need to put a use case for verification because the raffle system is not an actor correct?

2) However, if the actor is another staff for the raffle system (where he or she sorts out the raffle manually), would the use case for verification be applicable?

3) If so, is this the correct diagram to illustrate (2)?

Update entry -- <<includes>> --> Verification

Answer 1

Your diagram has a couple of errors:

• System is never an external actor. It's acting inside the system under consideration represented by the boundary.
• Therefore Verification is not a valid use case. It's some internal functionality.
• <<extend>> works the other way round (move the arrow pointing to the other side).
• The same for <<include>> .
• Verification is not a name for a use case. It needs predicate/subject and optionally an object.
• Generalization (to Update entry ) is a bad idea for UCs and probably not what you wanted to show here (so what is the intention here?).
• Basically UCs are about added value brought to their primary actors. They are not about functions involved. Try to get this focus and avoid anything that tends to be functional decomposition!

Edit

1. Exactly.
2. If someone's there to do that, you have an actor and such a UC (though it shall be named correctly).
3. This can be correct. Whether it is correct depends on the requirements to the system under consideration (what you finally want to achieve)