For what types of tasks is an Activity Diagram needed?

Activity Diagram is used for modeling workflows and business processes where the sequence of actions and control flow are important. It is suitable for tasks related to:

• Describing business processes and workflows.
• Modeling algorithms with parallel and sequential actions.
• Visualizing the logic of event handling or operations within a system.
• Analyzing complex processes with branching and conditions.

For example, it is convenient to use an Activity Diagram to describe the process of placing an order in an online store or processing a request in a support service.