This is a structural representation of the functions within a system, that is independent of how it is implemented.

This is a diagram showing the business processes and how it will operate.

This is a diagram showing how the system with interact with its environment.

ATM example

This is peace of text attached to each use case, this describes what internal mechanism of the use is

External things that interact with the system, doesn't have to be human

Describes 1 function that the system can do

Represented by the ovals

Defines what is internal vs what is external to the system

Represented by the rectangle around all the use cases

Links the actors to the use cases

Represented by lines

Links use cases, when a use case is a part of a larger use case

Example being using your credit card is a part of buying clothing

Represented by a dashed arrow

Between different use cases,

It is a optional version of include

Represented by a dashed arrow

Relationship between a general element and a specific element that gives more information

child use case inherits the features of the parent use case

Represented by a arrow

shows how many uses cases can interact with a actor

Represented: 1 customer, 0 to infinity attempts

• Assigns responsibility to people