Deterrent Examples
In this chapter we would like to present some real-world deterrent examples, which definitely should not inspire you.
Example 1
- Names should start wiht the capital letter
- Actors do not need to be stereotyped
- Use case names should have the form
<verb> <direct object> - If the analyst decides to include reference to the related business process (the grey "use case"), it should not definitelly be modeled as a use case, let alone to be place within the system boundary and connected using the include relationship
- Use cases should be at user-goal level without implementation details - the fact the messages are delivered using push notifications does not belong to use case
- Deals with registration is overcomplicated name - Sign up is much better
- Reads incoming messages is not a well-chosen name either. Use case should also reflect what the user wants from the system. User wants do display messages so the use case should be named Display messages
Example 2
- Missing system boundary
- Names should not be in third person
- Typical functional decomposition - many includes
- 'Works with payment' says nothing and serves only as a package of other functionalities. It is not a use case.
- Confirms payment is just a step, functionality, it should not be a use case
Example 3
- It is not a use case diagram at all
- My account is not a system, it is a section
- Author just used use case notation to describe which services are called when two functions are triggered - don't do this
Example 4
- Requirements should be connected directly to the use case which realizes them
- Use case called "Requirements" is a nonsense
Example 5
- Use case diagram represents use cases for just one system. Deviding the boundaries to two system is not correct.
- Actors should always be placed outside of the system boundary
- If you decide to model a system as an actor (which we do not recommend), it should be really a system. API is not a system.
Example 6
Use cases are tricky, even companies like IBM struggle to get them right:
Example 7
This example is from a tutorial presented by an online drawing tool, used by thousands of proffessionals:
Example 8
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