For large and complex systems, each module may be the system boundary.The system boundary is potentially the entire system as defined in the requirements document.Actors may be connected to use cases by associations, indicating that the actor and the use case communicate with one another using messages.The participation of an actor in a use case is shown by connecting an actor to a use case by a solid link.Each Actor must be linked to a use case, while some use cases may not be linked to actors.System function (process – automated or manual).Actor has a responsibility toward the system (inputs), and Actor has expectations from the system (outputs).can be an instructor and also a researcher Similar to the concept of user, but a user can play different roles.Someone interacts with a use case (system function).

For example, a bank cardholder might need to use an ATM to get cash out of their account. There is no rocket science to it at all: a usage case is simply a reason to use a system.

The functional goal that the actor achieves using the system the reason for using the system.Ī use case diagram is a visual representation of the relationships between actors and use cases together that documents the system’s intended behavior.

An actor is a type of user (for example, cardholder) that interacts with the system.

Thus, there are three key things we need to know to describe a use case: Note: A use case describes how a type of user (or known as an actor) uses a system to achieve a particular user goal. The test planner can extract scenarios from the use cases for test cases. Use cases are also very helpful for writing acceptance test cases. Use cases are developed during requirements elicitation and are further refined and corrected as they are reviewed (by stakeholders) during analysis. Use case diagrams are used during requirements elicitation and analysis as a graphical means of representing the functional requirements of the system. A use case typically represents a major piece of (end-to-end) functionality that is complete from beginning to end. View and play PowerPoint presentations online.Ī use case, a concept invented by Ivar Jacobson at 1992, is a sequence of transactions performed by a system that yields an outwardly visible, measurable result of value for a particular actor.

Free use case diagram online