What is extends and includes in use case?

Include = reuse of functionality (i.e. the included functionality is used or could be used elsewhere in the system). Include therefore denotes a dependency on another use case. Extends = adding (not reusing) functionality and also any optional functionality.

How do you show include and extend in use case diagram?

Include relationship may or may not appear on its own as a behavior sequence. Extend relationship is one where the extension use case adds itself to the base use case. In UML notation the extend relationship is annotated with the <> keyword and a dashed arrow pointing towards the base use case.

What is difference between extend and include example?

In simple words, the difference between include and extend is that ‘include’ is for adding methods only to an instance of a class and ‘extend’ is for adding methods to the class but not to its instance.

What are extension points in use cases?

In UML models, an extension point identifies the point in the base use case where the behavior of an extension use case can be inserted. The extension point is specified for a base use case and is referenced by an extend relationship between the base use case and the extension use case.

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 are basic elements of a use case diagram?

Use case diagram components

• Actors: The users that interact with a system. An actor can be a person, an organization, or an outside system that interacts with your application or system.
• System: A specific sequence of actions and interactions between actors and the system.
• Goals: The end result of most use cases.

What is use case diagram with example?

A use case diagram is a dynamic or behavior diagram in UML. Use case diagrams model the functionality of a system using actors and use cases. Use cases are a set of actions, services, and functions that the system needs to perform.

What are the different types of use cases?

There are basically two types of use cases analysts can draw from: Business Use Cases and System Use Cases. Business Use Cases are more about what a user expects from a system while System Use Cases are more about what the system does. Both use case types can be represented by diagrams or text.

What is the meaning of use cases?

A use case is a written description of how users will perform tasks on your website. It outlines, from a user’s point of view, a system’s behavior as it responds to a request. Each use case is represented as a sequence of simple steps, beginning with a user’s goal and ending when that goal is fulfilled.

What are the three main parts of a use case scenario?

Preconditions – what must be true or happen before and after the use case runs. Triggers – this is the event that causes the use case to be initiated. Main success scenarios [Basic Flow] – use case in which nothing goes wrong. Alternative paths [Alternative Flow] – these paths are a variation on the main theme.

What are the elements of use case?

Elements of a Use Case

• Actor – anyone or anything that performs a behavior (who is using the system)
• Stakeholder – someone or something with vested interests in the behavior of the system under discussion (SUD)
• Primary Actor – stakeholder who initiates an interaction with the system to achieve a goal.

What is a use case with example?

A use case is a description of how a person who actually uses that process or system will accomplish a goal. It’s typically associated with software systems, but can be used in reference to any process. For example, imagine you’re a cook who has a goal of preparing a grilled cheese sandwich.