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BPMN symbols & elements

BPMN looks complicated, but nearly every diagram is built from a small set of shapes. Here's what each one means — a practical cheat sheet for reading and building BPMN 2.0.

BPMN 2.0 reference · Reading time ~7 minutes

On this page

1. Events (circles)
2. Activities & tasks (rounded rectangles)
3. Gateways (diamonds)
4. Connecting objects (arrows)
5. Pools & lanes (swimlanes)
6. Artifacts
Reading tips

1. Events — circles

An event is something that happens during the process. The border tells you where it sits in the flow; an inner icon tells you what kind of trigger it is.

Symbol	Border	Meaning
Start event	Thin single line	Where the process begins. Every process has at least one.
Intermediate event	Double line	Something that happens between start and end — a message arrives, a timer elapses.
End event	Thick single line	Where a path of the process finishes.
Message event	Envelope icon	A message is sent or received.
Timer event	Clock icon	A delay, deadline, or scheduled trigger.

2. Activities & tasks — rounded rectangles

An activity is a piece of work performed in the process. The most common is the task — a single step such as "Send invoice" or "Review application". Name tasks with a verb + object so the diagram reads like a checklist.

Symbol	Meaning
Task	An atomic unit of work.
Sub-process	A task that contains its own smaller process; can be collapsed or expanded.
User task	Work done by a person interacting with software.
Service task	Work done automatically by a system or service.

3. Gateways — diamonds

Gateways control how the flow branches and merges. This is where most of BPMN's precision lives, so it's worth knowing the main types.

Gateway	Marker	Meaning
Exclusive (XOR)	× or empty diamond	Take exactly one path based on a condition — "Payment received? Yes / No".
Parallel (AND)	+	Take all paths at once; they run in parallel and later synchronize.
Inclusive (OR)	○	Take one or more paths, whichever conditions are true.
Event-based	Pentagon in circle	The path taken depends on which event happens first.

Key rule: what a gateway splits it should later join with a matching gateway. An AND split must be closed by an AND join so the parallel paths re-synchronize; an XOR split is merged by an XOR join. Mismatched splits and joins are the most common way to build a diagram that can't actually run.

4. Connecting objects — arrows

Connector	Looks like	Meaning
Sequence flow	Solid arrow	The order of steps within one participant.
Message flow	Dashed arrow	A message passed between participants (between pools).
Association	Dotted line	Links an artifact (like a note or data object) to a flow element.

5. Pools & lanes — swimlanes

Swimlanes answer "who does what".

A pool represents a participant — an organization, a customer, or a system. Separate pools communicate only through message flows.
A lane is a subdivision of a pool — for example, departments or roles within one company: Sales, Finance, Warehouse.

Placing each task in the right lane makes hand-offs obvious: you can literally see the work cross from one role to another.

6. Artifacts

Artifacts add context without changing the flow:

Data object — a document or piece of information used or produced by a task.
Group — a visual grouping of related elements.
Text annotation — a plain note that explains part of the diagram.

Reading tips

Follow the solid arrows from the start circle to the end circle — that's the happy path.
At every diamond, ask "what decides which way this goes?"
Dashed arrows always cross between pools — that's communication, not sequence.
If a split has no matching join, treat it as a red flag.

Skip the manual drawing

Describe your process in plain English and get a diagram with the right events, gateways and lanes already in place.

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