Uml Sequence If
Posted : admin On 1/25/2022Notation Description | Visual Representation |
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Actor
Note that:
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Lifeline
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Activations
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Call Message
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Return Message
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Self Message
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Recursive Message
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Create Message
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Destroy Message
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Duration Message
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Note A note (comment) gives the ability to attach various remarks to elements. A comment carries no semantic force, but may contain information that is useful to a modeler. |

A UML sequence diagram shows how a set of objects interact in a process over time. It shows the messages that pass between participants and objects in the system, and the order in which they occur. Newer desktop versions Web 2007–2010. To understand what a sequence diagram is, it's important to know the role of the Unified Modeling Language, better known as UML. UML is a modeling toolkit that guides the creation and notation of many types of diagrams, including behavior diagrams, interaction diagrams, and structure diagrams. UML Sequence Diagrams are interaction diagrams that detail how operations are carried out. They capture the interaction between objects in the context of a collaboration. Sequence Diagrams are time focus and they show the order of the interaction visually by using the vertical axis of the diagram to represent time what messages are sent and wh.
Uml Sequence If It Takes

An alternative combined fragment is used to specify an area of a group of lifelines/ actors to show conditional flow in a sequence diagram. It also models the if-then-else logic in the sequence diagram. In this article, we will demonstrate how to draw a simple sequence diagram by using an alternative combined fragment.
- Create a sequence diagram as follows:
- Select Alt. Combined Fragment in the diagram toolbar. Press on the blank area of the diagram and drag to cover the Person and ATM Machine lifeline.
Create an alternative combined fragment
- Draw a message from ATM Machine lifeline to Person lifeline in the upper compartment of the alternative combined fragment. Name it as Ask for password. Draw another message from ATM Machine lifeline to Person lifeline in the lower compartment of the alternative combined fragment afterwards. Name it as Display invalid card.
Draw two messages in an alternative combined fragment
- Right-click on the combined fragment and select Open Specification… from the pop-up menu to open the Combined Fragment Specification dialog box.
- When the Combined Fragments Specification window appears, open the Interaction Operands tab, select Operand, and then click Open Specification… button. In the Interaction Operand Specification dialog box, open the Guard tab and enter Valid card in Constraint text field. Click OK button to confirm the changes.
Enter Valid card for Operand
- Similarly, enter Invalid card in Constraint text field for Operand2by following the previous step.
- Guard conditions are displayed in the alternative combined fragment as shown below:
Guard conditions are displayed
How to try the sample
Uml Sequence Diagram Interaction
Download ATM machine and then unzip it to get the .vpp file.