Sequence diagram maker

Before drawing, determine the specific story you’re telling. A sequence diagram should focus on a single scenario rather than trying to map an entire system. Identify the trigger that starts the process and the boundary where does the interaction ends.

List all the participants involved in the process. Use stick figures for external actors and rectangles for internal system objects or components.

Arrange the participants horizontally across the top and place the initiator on the far left. Draw vertical lines extending down from each participant. Events at the top happen first, and those further down happen later.

Represent interactions with horizontal arrows between lifelines. Use different arrow styles to distinguish between synchronous and asynchronous messages. For example, use solid lines for calls and dashed lines for returns.

Use thin vertical rectangles on the lifelines to show when an element is actively processing the task. The bar starts when the message is received and ends when a return message is sent.

Make sure the sequence diagram flows logically from top to bottom. Check to make sure every synchronous message has a corresponding return message and that the logic aligns with your requirements.