What is the relationship between use case and actors?

What is the relationship between use case and actors?

An association is the relationship between an actor and a business use case. It indicates that an actor can use a certain functionality of the business system—the business use case: Unfortunately, the association does not give any information about the way in which the functionality is used.

What is the role of an actor in a use case?

An actor specifies a role played by a user or any other system that interacts with the subject. ... Actors are always outside the system and interact directly with it by initiating a use case, provide input to it, and/or receive outputs from it.

Does an actor have to be linked to a use case?

Few things to note. An actor must be associated with at least one use case. An actor can be associated with multiple use cases. Multiple actors can be associated with a single use case.

Which use case relationships connects the actor to the use case?

The behavioral relationship communicates is used to connect an actor to a use case. Remember that the task of the use case is to give some sort of result that is beneficial to the actor in the system. Therefore, it is important to document these relationships between actors and use cases.

What is the difference between a user story and a use case?

A user story — some people call it a scenario — expresses one very specific need that a user has. It's usually written out as a couple of sentences. ... A use case is similar to a user story, because it also describes one specific interaction between the user and the software.

What are examples of use cases?

Example Use Cases

• A housekeeper does laundry on a Wednesday.
• She washes each load.
• She dries each load.
• She folds certain items.
• She irons some items.
• She throws away certain items.

What is an actor in a use case diagram?

An actor in use case modeling specifies a role played by a user or any other system that interacts with the subject. An Actor models a type of role played by an entity that interacts with the subject (e.g., by exchanging signals and data), but which is external to the subject.

When would you use a use case diagram?

In UML, use-case diagrams model the behavior of a system and help to capture the requirements of the system. Use-case diagrams describe the high-level functions and scope of a system. These diagrams also identify the interactions between the system and its actors.

How are actors involved in a use case?

Actors are always outside the system and interact directly with it by initiating a use case, provide input to it, and/or receive outputs from it.

Is it possible to generalize actors and use cases?

Is it Possible to Generalize Actors and Use Cases There may be instances where actors are associated with similar use cases while triggering a few use cases unique only to them. In such instances, you can generalize the actor to show the inheritance of functions. You can do a similar thing for use case as well.

Do you consider all use cases as use cases?

So all of these can be considered as use cases. Top level use cases should always provide a complete function required by an actor. You can extend or include use cases depending on the complexity of the system. Once you identify the actors and the top level use case you have a basic idea of the system.

What are the objects in a use case diagram?

Use case diagrams consist of 4 objects. Actor. Use case. System. Package. The objects are further explained below. Actor. Actor in a use case diagram is any entity that performs a role in one given system. This could be a person, organization or an external system and usually drawn like skeleton shown below.