In some situations, this is done to simplify complex behaviors. The main reason for this is to reuse common actions across multiple use cases. The dotted line going away from the main use case: Include relationship show that the behavior of the included use case is part of the including (base) use case. The extended (base) use case must be meaningful on its own. The extending use case is usually optional and can be triggered conditionally. The extending use case is dependent on the extended (base) use case. 3 characteristics of an extend use case are: Here are a few things to consider when using the > relationship.

As the name implies it extends the base use case and adds more functionality to the system. The dotted arrows toward the Main Use Case = Extend relationships.

The rectangular box = the System Boundary An actor to the right would indicate someone in the back end interacting with the system. An actor to the left of the diagram typically represents the a person that will input a system. I will break down what each component means for you.Īctor = Stakeholder.

Use-case engage the user in the requirement process.īefore we get into the steps of building use cases I wanted to break down the components of a Use Case diagram as well as that of a use case Use case Diagram Components:.

Use-cases force developers to think from the end user perspective.

Use-cases are relatively easy to write and read compared to the traditional requirement methods.

It is an easy means of capturing the functional requirement with a focus on value added to the user.

The method creates a document that describes all the steps taken by a user to complete an activity.Ī use-case provides the following benefits − The use case is made up of a set of possible sequences of interactions between systems and users in a particular environment and related to a particular goal. This article goes over 3 Steps to Building UML Use Case Diagrams and Use Case NarrativesĪ use case is a methodology used in system analysis to identify, clarify and organize system requirements.

Online shopping use case diagram uml