Activity Diagrams Used in Software Development

System Design Article Series,

1. Use Case View in Software Development
2. System Sequence Diagram Used in Software Development

Activity Diagrams

The "Unified Modeling Language" provides the foundation for the system flow diagram. This diagram illustrates how the user interacts with the system for each use case. How the system will function, and how the user will be able to interact with it.

Unified Modeling Language (UML) activity diagrams are a particular sort of behavioral diagram that show the flow and order of activities or processes within a system or business process. They show the numerous tasks, decisions, and actions that go into a process, emphasizing the sequence of events and the connections between distinct components. Activity diagrams are frequently used to represent intricate business processes, use cases, and software system Behaviour.

Here are some key elements and symbols commonly used in activity diagrams,

1. Initial Node: Denotes the starting point of the activity diagram. It is usually represented by a small, filled circle.
2. Activity or Action: Represents a specific task or operation within the system or process. It is depicted as a rounded rectangle with its name inside.
3. Decision or Branching Point: Indicates a point where a decision needs to be made and the flow of execution branches based on a condition. It is represented by a diamond-shaped symbol, with different outgoing arrows indicating the possible paths based on conditions.
4. Merge: This shows the merging of multiple paths back into a single flow of execution. It is depicted as a diamond-shaped symbol with multiple incoming arrows and a single outgoing arrow.
5. Fork: Represents the splitting of the flow of execution into multiple concurrent paths. It is depicted as a bar with multiple outgoing arrows.
6. Join: Indicates the joining of multiple concurrent paths back into a single flow of execution. It is depicted as a bar with multiple incoming arrows.
7. Final Node: Denotes the endpoint of the activity diagram. It is usually represented by a small, filled circle with a border.
8. Transition or Arrow: This represents the flow of control between different activities, actions, or decision points. It shows the sequence in which activities occur and is represented by arrows connecting the different elements.

Activity diagrams can also include additional elements, such as swim lanes, to represent different actors or organizational units responsible for the activities and objects or data stores to represent the data involved in the process.

By using activity diagrams, you can visually represent the flow of activities and decisions within a system or process, making it easier to understand, analyze, and communicate complex workflows or behavioral aspects of a software system or business process.

Some of the Examples of Activity Diagrams are given below.