Control Flow

The Control Flow connects the initial node of an activity diagram with the final node. In between, you can add several action nodes.

• Name

• Description

• Symbol Type

If the control flow starts from a decision, it has two more specific attributes.

Guard

Control flows that are starting from a decision node need to have a guard expression. A guard expression is an expression that evaluates to true or false, and specifies which control flow branch to follow from the decision node on. One of the guard expressions must be else to define the branch to follow when none of the guard expressions are true.

true

Follow this branch.

Control flows starting from decision node.

false

Do not follow this branch.

Order

If a decision node branches the control flow into multiple branches, order defines the order in which the guard expressions (see Guard above) should be evaluated. This is necessary in case multiple guard expressions evaluate to true. The else  expression does not need to have an order.

an integer

Order in which the guard expression on this control flow should be evaluated.

Control flows starting from decision node.

empty

Undefined order of evaluation.