Activity diagrams in LLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an activity diagram?

An activity diagram is a visual representation that shows the flow of actions or activities in a system or process, similar to a flowchart but focused on workflows.

beginner

What symbol represents the start of an activity diagram?

A filled black circle represents the start (initial node) of an activity diagram.

intermediate

How do activity diagrams show decision points?

Decision points are shown as diamonds where the flow splits based on conditions, like choosing a path at a fork in a road.

intermediate

What is the purpose of swimlanes in activity diagrams?

Swimlanes divide the diagram into sections to show which actor or part of the system is responsible for each activity, like lanes in a swimming pool.

advanced

How does an activity diagram represent parallel activities?

Parallel activities are shown using a fork node (a thick horizontal or vertical bar) that splits the flow into multiple concurrent paths.

Which symbol marks the end of an activity diagram?

A A rectangle

B A diamond

C A filled black circle

D A filled black circle with a border

The end of an activity diagram is shown by a filled black circle inside a larger circle, called the final node.

What does a diamond symbol represent in an activity diagram?

A Start of the process

B Decision point

C Parallel fork

D Activity step

Diamonds represent decision points where the flow branches based on conditions.

What is the main use of swimlanes in activity diagrams?

A To show parallel activities

B To indicate start and end

C To assign activities to actors or departments

D To represent decisions

Swimlanes organize activities by who or what performs them.

How are concurrent activities shown in an activity diagram?

A Using fork and join nodes

B Using diamonds

C Using swimlanes

D Using arrows only

Fork nodes split flow into parallel paths; join nodes merge them back.

Which of the following is NOT typically shown in an activity diagram?

A Detailed class structure

B Actors responsible for activities

C Flow of activities

D Decision points

Class structure is shown in class diagrams, not activity diagrams.

Explain the main components of an activity diagram and their roles.

Think about how a process flows and who does what.

Describe how activity diagrams help in understanding system workflows.

Imagine explaining a recipe or a daily routine step-by-step.