Activity diagram is another important diagram in UML to describe the dynamic aspects of the system. Activity diagram is basically a flowchart to represent the flow from one activity to another activity. The activity can be described as an operation of the system.

Activity diagram for online shopping system The activity diagram used to describe flow of activity through a series of actions. Activity diagram is a important diagram to describe the system. The activity described as a action or operation of the system.

How to Draw an Activity Diagram

1. Step 1: Figure out the action steps from the use case. Here you need to identify the various activities and actions your business process or system is made up of.
2. Step 2: Identify the actors who are involved.
3. Step 3: Find a flow among the activities.
4. Step 4: Add swimlanes.

Action or Activity State – An activity represents execution of an action on objects or by objects. We represent an activity using a rectangle with rounded corners. Basically any action or event that takes place is represented using an activity. Figure – notation for an activity state.

Both activity and state chart diagrams model the dynamic behavior of the system. Activity diagram is essentially a flowchart showing flow of control from activity to activity. A state chart diagram shows a state machine emphasizing the flow of control from state to state.

UML State machine diagram and activity diagram are both behavioral diagrams but have different emphases. Activity diagram is flow of functions without trigger (event) mechanism, state machine is consist of triggered states.

Swimlanes are used to show which activities are performed by which organisation in the activity diagram. The lanes are boundaries are drawn and the activities of a particular organisation are drawn in the same lane as that of the organisation. Swimlanes have to be ordered in a Logical Manner.

How to create a swimlane diagram in Word

1. Prepare a new document. First, open a new Word document.
2. Create swimlanes. Next, create your swimlanes by going to Insert > Shapes and selecting the Rectangle shape.
3. Label swimlanes. Label your swimlanes by creating a text box from the Insert tab.
4. Build a flowchart.
5. Format shapes.

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.

Basic Sequence Diagram Notations

• Class Roles or Participants. Class roles describe the way an object will behave in context.
• Activation or Execution Occurrence. Activation boxes represent the time an object needs to complete a task.
• Messages.
• Lifelines.
• Destroying Objects.
• Loops.
• Synchronous Message.
• Asynchronous Message.

The sequence diagram is a good diagram to use to document a system’s requirements and to flush out a system’s design. The reason the sequence diagram is so useful is because it shows the interaction logic between the objects in the system in the time order that the interactions take place.

A sequence diagram simply depicts interaction between objects in a sequential order i.e. the order in which these interactions take place. We can also use the terms event diagrams or event scenarios to refer to a sequence diagram. Sequence diagrams describe how and in what order the objects in a system function.

Selection and Loops in a Combination

1. if -> (opt) [condition]
2. if/else -> (alt) [condition], separated by horizontal dashed line.
3. loop -> (loop) [condition or items to loop over]

In UML, class diagrams are one of six types of structural diagram. You can use class diagrams to model the objects that make up the system, to display the relationships between the objects, and to describe what those objects do and the services that they provide. …

A design class diagram (DOD) illustrates the specifications for software classes and interfaces (for. example, Java interfaces) in an application.

The advantages of the class diagram Class diagrams give you a sense of orientation. They provide detailed insight into the structure of your systems. At the same time they offer a quick overview of the synergy happening among the different system elements as well as their properties and relationships.