The 4 Main Elements of a BPMN Diagram

Business Process Model and Notation (BPMN) is one of the most powerful tools in a Business Analyst’s toolkit. Whether you're mapping out a customer journey, documenting system flows, or clarifying internal operations, BPMN helps you create clear, standardized, and professional diagrams.

BPMN (Business Process Model and Notation) diagrams are built from four main element categories: flow objects, connecting objects, swimlanes, and artifacts. Once you understand these, you’ll be well on your way to mastering business process modeling.

Now, let’s explore the four key building blocks.

1. Flow Objects: The Core Actions and Events

Flow objects are the backbone of any process. They represent what actually happens in a business flow.

🔵 Events

Events mark something that starts, changes, or ends a process. They are usually circles.

• Start Event: Triggers the process (e.g., form submission)

  

• Intermediate Event: Happens in the middle (e.g., waiting for a reply)

  

• End Event: Marks completion (e.g., email sent)

  

🟦 Activities

Activities are tasks or work that needs to be done. They are shown as rounded rectangles.

• Task: A single unit of work (e.g., "Send Invoice")

  

• Sub-process: A process that can be broken into smaller parts

  

• Call Activity: A reusable activity that references another process

  

🔷 Gateways

Gateways control decision points and branching logic in the process. They look like diamonds.

• Exclusive Gateway (XOR): Only one path is taken

  

• Parallel Gateway (AND): All paths are taken simultaneously

  

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2. Connecting Objects: The Arrows of Communication

Once you have events, tasks, and decisions, you need to connect them to show how things flow.

➡️ Sequence Flow

Shows the order of activities (e.g., from Task A to Task B)

🔁 Message Flow

Represents communication between participants (e.g., between customer and system)

📎 Association

Used to link text annotations, data, or artifacts to elements (adds extra info)

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3. Swimlanes: Who Does What

Swimlanes help you organize your diagram by showing who is responsible for each step.

Pool

Represents an independent participant — usually a department, company, or external party.

Lane

A subdivision within a pool, representing a specific role, system, or person.

For example:

• Pool: Customer Service

• Lanes: Agent, Manager

Swimlanes make complex processes easier to follow by clearly showing responsibilities.

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4. Artifacts: Extra Information and Context

Artifacts don’t change the flow, but they add useful context and documentation.

Data Objects

Represent data that is input/output in a task (e.g., "Order Form")

Annotations

Used to add notes or explanations for readers

Group

Used to visually group related elements without affecting flow

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Final Thoughts

Learning BPMN starts with understanding these four foundational elements:

1. Flow Objects – The core steps of the process

2. Connecting Objects – How things link together

3. Swimlanes – Who’s doing what

4. Artifacts – Supporting info that adds clarity

Once you master these, you’ll be able to create clear, structured, and insightful process diagrams — a must-have skill for any Business Analyst.