example of use case diagram with scenario online ordering system

Hence, when a system is analyzed to gather its functionalities, use cases are prepared and actors are identified. These requirements are mostly design requirements. Use case diagrams are used to gather the requirements of a system including internal andĮxternal influences. We will look into some specific purpose, which will distinguish it from other four diagrams. However, this definition is too generic to describe the purpose, as other four diagrams (activity, sequence, collaboration, and Statechart) also have the same purpose. The purpose of use case diagram is to capture the dynamic aspect of a system. Hence to model the entire system, a number of use case diagrams are used.

A single use case diagram captures a particular functionality of a system. The diagram is used to model the system/subsystem of an application.

Use case diagrams consists of actors, use cases and their relationships. These internal and external agents are known as actors. Now as we have to discuss that the use case diagram is dynamic in nature, there should be some internal or external factors for making the interaction. In UML, there are five diagrams available to model the dynamic nature and use case diagram is one of them. Only static behavior is not sufficient to model a system rather dynamic behavior is more important than static behavior. Dynamic behavior means the behavior of the system when it is running/operating. To model a system, the most important aspect is to capture the dynamic behavior.

Example of use case diagram with scenario online ordering system