When I first modeled business processes, I avoided complex gateways. Honestly, they looked intimidating. However, once I understood them, I realized how powerful they can be. In this post, I’ll show you what complex gateways do, when to use them, and how to model them with just a few BPMN elements. Let’s dive in.
What is Process Management?
Process management helps me streamline how work gets done. It allows me to visualize tasks, define responsibilities, and monitor progress. With clear processes, teams avoid confusion. As a result, productivity increases, and mistakes decrease. Therefore, I always start with a well-structured process model before any project takes off.
Why Do We Need BPMN in Process Management?
BPMN gives me a standard language for modeling processes. It’s visual. It’s precise. And best of all, it works across teams and tools. Whether I collaborate with developers, analysts, or managers, everyone understands the diagram. Because BPMN is widely supported, I can even use it in tools like Camunda for real execution.
Using Complex Gateways in BPMN 2.0
Now let’s get to the core topic—complex gateways in BPMN 2.0. Unlike other gateways, complex gateways allow me to define custom logic for when process paths merge or split. They aren’t used often, but sometimes, they’re exactly what I need.
A Simple Example
Here’s a situation I faced: I had two tasks running in parallel. One team checked a supplier list. The other explored alternatives online. I wanted to continue to the next step—“Place Order”—as soon as one of the two finished. However, I didn’t want the second result to trigger the order again.
Using a parallel or inclusive gateway didn’t work. They either waited too long or triggered the same task multiple times. So, I used a complex gateway.
Camunda-Compatible Diagram Structure
- Start Event
- Task: “Check Supplier List”
- Task: “Search Alternatives”
- Complex Gateway (Join with custom condition: 1 of 2 tasks complete)
- Task: “Place Order”
- End Event
In Camunda, I annotate the complex gateway to define the behavior: continue when at least one token arrives.
Another Case: Conditional Synchronization
I had another case where I asked three friends to rate a pizza place. I wanted to act as soon as two replied. Again, the complex gateway helped.
I modeled:
- Start Event
- Task 1: “Ask Friend A”
- Task 2: “Ask Friend B”
- Task 3: “Ask Friend C”
- Complex Gateway (Join after 2 tokens)
- Task: “Decide on Pizza”
- End Event
This logic is hard to model with standard gateways. But with a complex gateway, it’s clear and executable.
Final Thoughts
Although I don’t use complex gateways daily, I’m glad I know how. They give me control over advanced logic without cluttering my model. Whenever I need to synchronize based on flexible conditions, I go for them. And thanks to Camunda, I can even execute these models.
To sum up, complex gateways in BPMN 2.0 are a hidden gem. They solve rare but tricky cases in process logic. Use them when you need that extra bit of control.
Credits: The diagrams were created with Camunda (opens in a new tab).
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