When I first learned about Business Process Model and Notation (BPMN), I felt overwhelmed. After all, BPMN seemed complicated at first glance. However, I quickly realized it’s actually straightforward. In this post, I’ll simplify BPMN core elements for you. We’ll explore how events, tasks, and sequence flows work together in practical terms.
What is BPMN 2.0?
First of all, BPMN 2.0 is a standard notation used to visualize business processes clearly and consistently. It helps everyone involved understand the exact flow and activities required to achieve business goals. Consequently, BPMN makes complex processes easier to manage and improve.
Events, Tasks, and Sequence Flows: BPMN Core Elements
To start with, let’s dive into the basics. Events, tasks, and sequence flows are the essential BPMN core elements. These three elements form the simplest possible process model but remain fundamental even in highly complex processes.
Consider a practical example: taking medicine for a headache. First, the process begins because someone experiences a headache. Next, they must purchase medication, then take the medicine, and finally drink water. At the end, the headache disappears. Clearly, this example highlights all three BPMN core elements. In BPMN this process would look like this.
Tasks
Tasks represent the core of every BPMN model. Simply put, a task shows that something needs to be done. Without tasks, the process can’t deliver any outcome. Technically, tasks belong to a broader category called activities, which also includes subprocesses. In our diagram, for example, buying medicine is a task.
Events
Events indicate significant occurrences within a process—before, during, or at the end. Initially, we use simple “blank” events, but later you’ll learn about more complex event types. Specifically, there are three kinds of events:
- Start Events: They trigger the process. Something external happens, and the process responds to this event.
- Intermediate Events: These mark milestones or statuses within the process. Though less common, they can be very useful for tracking progress.
- End Events: They signify the end of a specific process path. After reaching this point, the process concludes.
Additionally, understanding event types is crucial:
- Start events are always “catching events.” That means they happen externally, and the process must wait or respond accordingly.
- Intermediate events can either occur externally (catching) or be triggered internally (throwing). Blank intermediate events usually represent internally triggered milestones.
- End events always occur due to the process itself. Thus, they can’t happen independently from it.
Take the event of taking the medicine as an intermediate event.
Sequence Flows
Finally, sequence flows define the logical and temporal order of events and tasks. Think of them as the paths that guide the workflow. When the process begins, a “token” is created. Subsequently, this token travels through tasks and events via the sequence flows. Eventually, it reaches the end event, where it disappears. Consequently, the process instance also ends. The sequence flow in our example is the arrows from left to right.
Final Thoughts
Overall, mastering BPMN core elements isn’t as challenging as it initially appears. Once I grasped these foundational concepts—events, tasks, and sequence flows—I could confidently model and understand business processes. Hopefully, now you feel ready to apply BPMN effectively in your own projects.
Credits: The diagrams are created by Camunda (opens in new tab).
