UML Use Case Diagram. Design Elements

The vector stencils library "UML use case diagrams" contains 25 symbols for the ConceptDraw PRO diagramming and vector drawing software.
"Use case diagrams are usually referred to as behavior diagrams used to describe a set of actions (use cases) that some system or systems (subject) should or can perform in collaboration with one or more external users of the system (actors). Each use case should provide some observable and valuable result to the actors or other stakeholders of the system. ...
Use case diagrams are in fact twofold - they are both behavior diagrams, because they describe behavior of the system, and they are also structure diagrams - as a special case of class diagrams where classifiers are restricted to be either actors or use cases related to each other with associations. ...
Use case is usually shown as an ellipse containing the name of the use case. ...
Name of the use case could also be placed below the ellipse. ...
If a subject (or system boundary) is displayed, the use case ellipse is visually located inside the system boundary rectangle. Note, that this does not necessarily mean that the subject classifier owns the contained use cases, but merely that the use case applies to that classifier. ...
A list of use case properties - operations and attributes - could be shown in a compartment within the use case oval below the use case name. ...
Use case with extension points may be listed in a compartment of the use case with the heading extension points. ...
A use case can also be shown using the standard rectangle notation for classifiers with an ellipse icon in the upper right-hand corner of the rectangle and with optional separate list compartments for its features. ...
Subject (sometimes called a system boundary) is presented by a rectangle with subject's name, associated keywords and stereotypes in the upper left corner. Use cases applicable to the subject are located inside the rectangle and actors - outside of the system boundary. ...
Standard UML notation for actor is "stick man" icon with the name of the actor above or below of the icon. Actor names should follow the capitalization and punctuation guidelines for classes. The names of abstract actors should be shown in italics. ...
Custom icons that convey the kind of actor may also be used to denote an actor, such as using a separate icon(s) for non-human actors. ...
An actor may also be shown as a class rectangle with the standard keyword «actor», having usual notation for class compartments ...
An actor can only have binary associations to use cases, components, and classes. ...
An association between an actor and a use case indicates that the actor and the use case somehow interact or communicate with each other.
Only binary associations are allowed between actors and use cases.
An actor could be associated to one or several use cases. ...
A use case may have one or several associated actors." [uml-diagrams.org/ use-case-diagrams.html]
The example "Design elements - UML use case diagrams" is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

This example of bank ATM UML activity diagram was created on the base of UML use case diagram of automated teller machine from the course "Thinking in Java, 2nd edition, Revision 9" by Bruce Eckel published on the website of the Computer Science and Electrical Engineering Department of the University of Maryland, Baltimore (UMBC).
"If you are designing an auto-teller, for example, the use case for a particular aspect of the functionality of the system is able to describe what the auto-teller does in every possible situation. Each of these “situations” is referred to as a scenario, and a use case can be considered a collection of scenarios. You can think of a scenario as a question that starts with: “What does the system do if...?” For example, “What does the auto-teller do if a customer has just deposited a check within the last 24 hours, and there’s not enough in the account without the check having cleared to provide a desired withdrawal?”
Use case diagrams are intentionally simple to prevent you from getting bogged down in system implementation details prematurely...
Each stick person represents an “actor,” which is typically a human or some other kind of free agent. (These can even be other computer systems, as is the case with “ATM.”) The box represents the boundary of your system. The ellipses represent the use cases, which are descriptions of valuable work that can be performed with the system. The lines between the actors and the use cases represent the interactions.
It doesn’t matter how the system is actually implemented, as long as it looks like this to the user."
[csee.umbc.edu/ courses/ 331/ resources/ tij/ text/ TIJ213.gif]
This automated teller machine (ATM) UML use case diagram example was created using the ConceptDraw PRO diagramming and vector drawing software extended with the ATM UML Diagrams solution from the Software Development area of ConceptDraw Solution Park.