UML Sequence Diagram. Design Elements

This example of automated teller machine (ATM) UML sequence diagram was created on the base of figure 5 "Sequence diagram" on the webpage "Message Sequence Charts and their Ilk" from the website of the University of California Irvine (UCI) Donald Bren School of Information and Computer Sciences.
"A UML sequence diagram or SD is similar to an MSC but written with a different notation. Presumably the same semantic issues arise, but possibly not since UML semantics are not well-defined. An example is shown in Figure 5.
The timelines are dotted rather than solid, and the name of the component is inside a box at the head of each timeline. The narrow rectangles apparently show when a component is active (unsure precisely what "active" means). An X on a timeline indicates that the component ceases to exist in some sense (unsure precisely how this is meant also). In the example, the Bank timeline has an X simply as an example (presumably the Bank does continue to exist)."
[www.ics.uci.edu/ ~alspaugh/ cls/ shr/ msc.html]
This example of bank ATM sequence diagram 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.

The vector stencils library "Bank UML sequence diagram" contains 34 shapes for drawing UML sequence diagrams.
Use it for object-oriented modeling of your bank information system.
"A sequence diagram shows, as parallel vertical lines (lifelines), different processes or objects that live simultaneously, and, as horizontal arrows, the messages exchanged between them, in the order in which they occur. This allows the specification of simple runtime scenarios in a graphical manner.
Diagram building blocks.
If the lifeline is that of an object, it demonstrates a role. Leaving the instance name blank can represent anonymous and unnamed instances.
Messages, written with horizontal arrows with the message name written above them, display interaction. Solid arrow heads represent synchronous calls, open arrow heads represent asynchronous messages, and dashed lines represent reply messages. ...
Activation boxes, or method-call boxes, are opaque rectangles drawn on top of lifelines to represent that processes are being performed in response to the message (ExecutionSpecifications in UML).
Objects calling methods on themselves use messages and add new activation boxes on top of any others to indicate a further level of processing.
When an object is destroyed (removed from memory), an X is drawn on top of the lifeline, and the dashed line ceases to be drawn below it ...
A message sent from outside the diagram can be represented by a message originating from a filled-in circle (found message in UML) or from a border of the sequence diagram (gate in UML)." [Sequence diagram. Wikipedia]
This example of UML sequence diagram symbols for the ConceptDraw PRO diagramming and vector drawing software is included in the ATM UML Diagrams solution from the Software Development area of ConceptDraw Solution Park.