What does Alt mean in sequence diagram?

What does Alt mean in sequence diagram?

alternative scenarios
alt is used to describe alternative scenarios of a workflow. Only one of the options will be executed. opt is used to describe optional step in workflow. For example, for online shop purchase sequence diagram you may use opt to describe how user can add gift wrapping if she wishes.

How do you add alternatives to a sequence diagram?

5 Answers

1. You can double click on the combined fragment and there will be one button, after clicking it you can add one operand. No need to manually copy and paste. – Hustlion.
2. Just a note: In my version 3.1. 1, they provides the option to add new operand in your step 2. – Rainning.
3. You deserve heaven. – Rafael Aguilar.

What is Alt combined fragment?

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.

What is opt in Plantuml?

opt : The InteractionOperatorKind opt designates that the CombinedFragment represents a choice of behavior where either the (sole) operand happens or nothing happens.

Where does the flow of a sequence diagram start?

A sequence diagram is structured in such a way that it represents a timeline which begins at the top and descends gradually to mark the sequence of interactions. Each object has a column and the messages exchanged between them are represented by arrows.

How do you add an alt to a sequence diagram visual paradigm?

Select Alt. Press on the blank area of the diagram and drag to cover the Person and ATM Machine lifeline. 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.

What is ref frame in sequence diagram?

ref Reference: refers to an interaction defined on another diagram. The frame is drawn to cover the lifelines involved in the interaction. You can define parameters and a return value.

How to create sequence diagrams?

Drag a Message shape onto the drawing page.

Glue the message endpoint without the arrowhead to a connection point on the lifeline of the object sending the message.

Glue the message endpoint with the arrowhead to a connection point on the lifeline of the object receiving the message.

Double-click the message, and then type or choose the message name, stereotype, sequence expression, and flow kind.

For a flat message or procedure call, choose the operation you want the message to generate.

What is an example of a sequence diagram?

Sequence diagrams are sometimes called event diagrams or event scenarios. 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.

What is a sequence diagram?

In software engineering, a system sequence diagram (SSD) is a sequence diagram that shows, for a particular scenario of a use case, the events that external actors generate, their order, and possible inter-system events.

When is sequence diagram used?

Used to model and visualise the logic behind a sophisticated function,operation or procedure.

They are also used to show details of UML use case diagrams.

Used to understand the detailed functionality of current or future systems.

Visualise how messages and tasks move between objects or components in a system.