BPMN
BPMN Symbols & Notation: Every Symbol Explained
Thom Uffing
BPMN symbols are the building blocks of every process diagram. Once you know the notation, you can read any BPMN model at a glance. This guide walks through the most important symbols, group by group, with a concrete example for each.
The official BPMN 2.0 notation contains dozens of symbols. Yet you only need a handful to get started. So we begin with the four core shapes and build up calmly from there.
The four core BPMN symbols
Almost every diagram is built from four basic shapes. Know these, and you understand the thread of any process:
Events (circles): something that happens, such as the start or end of a process.
Activities (rounded rectangles): a task or step, for example "Check invoice".
Gateways (diamonds): a decision point that splits or merges the process.
Flows (arrows): the connections that show the order.
These four groups are the heart of BPMN notation. The rest of this article zooms in on each one.
Events: start, intermediate and end
An event is a circle and marks that something happens. The thickness of the border tells you which type it is:
Start event (thin circle): the beginning of the process.
Intermediate event (double border): something that happens during the process, such as a received message.
End event (thick border): the end point of the process.
That way you immediately see where a process begins and stops. As a result, even a long diagram stays readable.
Activities: the actual work
An activity is a rounded rectangle and represents a task. This is where the work happens. Two common forms are:
Task: a single step, such as "Approve order".
Sub-process: a task with a plus sign, which itself contains several steps.
Use short, active labels (verb + object). That way, everyone reads the same step the same way.
Gateways: the decision points
A gateway is a diamond and determines the route through the process. The main variants are:
Exclusive gateway (X): choose exactly one path, based on a condition.
Parallel gateway (+): follow all paths at once.
Inclusive gateway (O): choose one or more paths.
Gateways make choices explicit. That prevents debate about "what happens if...".
Flows and swimlanes: connection and responsibility
Beyond the core symbols, two elements add context:
Sequence flow (solid arrow): the order of steps.
Message flow (dashed arrow): communication between parties.
Swimlanes (pools and lanes): rows that show who performs each step.
With swimlanes you tie each step to a role or department. As a result, responsibility becomes clear in a single glance.
A quick example
Picture a simple invoice approval. A start event kicks it off, the task "Check invoice" does the work, and an exclusive gateway asks "Approved?". Two sequence flows lead to either "Schedule payment" or "Return to sender", before an end event closes the process. That is a complete, readable BPMN diagram in just five symbols.
From symbols to a complete diagram
Knowing the symbols is step one. Combining them flawlessly into a validated model is step two. Drawing that by hand takes time and practice.
With ModelMatic you skip the drawing: you turn a conversation or text automatically into a correct BPMN 2.0 diagram, with the right symbols in the right place. New to the basics? Start with What is BPMN?. Want to get going right away? Try the AI BPMN generator.
Conclusion
BPMN symbols are simpler than they look. With events, activities, gateways and flows you capture almost any process. Add swimlanes and you also show who is responsible for what.
BPMN is maintained by the Object Management Group and is standardized internationally as ISO/IEC 19510:2013. You can find the full notation in the official OMG BPMN 2.0 specification and a friendly overview at bpmn.org. Start small, pick one process, and let AI create the first diagram with the right symbols for you.
