What are forks and joins used for in an activity diagram?

Forks are used to split an incoming transition into concurrent multiple transitions leading to different target states. Joins are used to merge concurrent multiple transitions into a single transition leading to a single target. They are semantic inverses.

When should we use forking joining and Swimlanes in an activity diagram?

It is not necessary to incorporate swimlane in the activity diagram. But it is used to add more transparency to the activity diagram. Forks and join nodes generate the concurrent flow inside the activity. A fork node consists of one inward edge and several outward edges.

Can we use join without fork in activity diagram?

You can use a join node anywhere you want, independent if you previously did a fork or not.

What is join node in activity diagram?

Merge node is a control node that brings together multiple incoming alternate flows to accept single outgoing flow. There is no joining of tokens. Merge should not be used to synchronize concurrent flows.

What is difference between fork and join in activity diagram?

A Fork notation in a UML Activity Diagram is a control node that splits a flow into multiple concurrent flows. This will have one incoming edge and multiple outgoing edges. A join node is a control node that synchronizes multiple flows. This will have multiple incoming edges and one outgoing edge.

How do you describe an activity diagram?

An activity diagram visually presents a series of actions or flow of control in a system similar to a flowchart or a data flow diagram. Activity diagrams are often used in business process modeling. They can also describe the steps in a use case diagram. Activities modeled can be sequential and concurrent.

What are Swimlanes in activity diagram?

Swimlane is a way in which the performed activities can be grouped by the same actor on an Activity diagram. To use swimlanes in an activity diagram, we need to arrange the activity diagram into vertical zones that are separated by the lines. On the other hand, Swimlane is not a part of the term UML.

How loop is represented in activity diagram?

The loop symbol has an appropriate representation in a construction consisting of four UML activity symbols – TASK, DECISION and two edges, where one edge leads from the TASK to DECISION and the other one leads backwards. The TASK represents the action and the decision node is used to resolve the loop condition.

What is the difference between fork and join in activity diagram?

How many types of nodes are there in activity diagram?

two types
There are two types of final node: activity and flow final nodes. The activity final node is depicted as a circle with a dot inside.

What is decision in activity diagram?

A decision node is a node in an activity at which the flow branches into several optional flows. There is exactly one incoming edge and an arbitrary number of outgoing edges, which each have a condition. A merge node is a node in an activity at which several flows are merged into one single flow.

What is activity diagram example?

An activity diagram is a behavioral diagram i.e. it depicts the behavior of a system. We can depict both sequential processing and concurrent processing of activities using an activity diagram. They are used in business and process modelling where their primary use is to depict the dynamic aspects of a system.

What does Fork and join mean in UML Activity diagram?

Fork and Join in UML Activity Diagrams (Forking and Joining) Fork / Join. A Fork notation in a UML Activity Diagram is a control node that splits a flow into multiple concurrent flows. This will have one incoming edge and multiple outgoing edges.

How are forks and joins used in activity?

The Fork/Join elements can be used to: These elements are used in both Activity and StateMachine diagrams, in either vertical or horizontal orientation. With respect to StateMachine diagrams, Forks and Joins are used as pseudostates. Other pseudostates include History states, Entry Points and Exit Points.

Can you use a join node in an activity diagram?

This node simply terminates the flow and does not affect other flows in the diagram. You can use a join node anywhere you want, independent if you previously did a fork or not. So what you did is correct.

When do you merge two flows after a fork?

For example in below diagram: A decision is used after a fork, the two flows coming out of the decision need to be merged into one before going to a join. Why?: