用例图UML，手机和客户是两个不同的角色还是相同的角色？ （日食）

Question

例如，我们如何知道客户和移动电话用户不是2个不同的人，例如，一位父母订购了合同电话，但她/他的孩子使用了合同电话，因此您将有2个演员，一个叫移动电话用户，另一个叫客户，否则只会是一个？

Answer 1

You'll notice from the comments that the answer to your question depends on information that you haven't provided. It doesn't really matter whether the mobile phone user and the customer are two different people or not. What does matter is the context in which they are interacting with the system.

For example, suppose you have two different people with bank accounts. One has a checking account, and one has a savings account. You could set them up as two different actors, but it's probably better to just have one customer actor. After all, you would probably have any number of customers, and each would have either type of account or both. So, the fact that one customer might not have a savings account isn't relevant to the system. The system has savings use cases and checking use cases and customers as a group interact with both.

So, how does that apply to your situation? It depends. It seems most likely, however, that most of the people paying for the phone service are also the people using the phone. In that case, there would just be one type of actor. If on the other hand, the system had distinctly different use cases for people who paid for the service and people who used it, and those people were often different, you could draw that distinction by using two different actors.