There are eight event categories which can be grouped into start, intermediate and end events:
Start Events: Define how the process or a sub-process begins — either normally or due to an interrupting/non-interrupting trigger.
Intermediate Events: Allow the process to catch, throw, or handle boundary events, either interrupting or not.
End Events: Shows where the process finishes as planned.
The Eight Event Categories are:
Start — Standard
Start — Event Sub-Process Interrupting
Start — Event Sub-Process Non-Interrupting
Intermediate — Catching
Intermediate — Boundary Interrupting
Intermediate — Boundary Non-Interrupting
Intermediate — Throwing
End — Standard
To explain the eight event categories, an example of an online retail order fulfilment is used:
Different event examples in order fulfilment:
Cancelling an order for fraud
Pausing while waiting for payment
Handling customer queries alongside main tasks
Sending notifications
And ending cleanly when delivery is confirmed
# | Category | Example in Order Fulfillment | How it Works |
1 | Start — Standard | Order Received — the process starts when an online order is submitted. | Triggers the main process when the normal condition occurs. |
2 | Start — Event Sub-Process Interrupting | Fraud Alert Detected — an interrupting event sub-process cancels the order processing if fraud is flagged. | Starts an embedded sub-process that interrupts the main flow immediately. |
3 | Start — Event Sub-Process Non-Interrupting | Customer Address Update — allows an address change to be processed alongside the ongoing order flow. | Starts an embedded sub-process without stopping the main process. |
4 | Intermediate — Catching | Wait for Payment Confirmation — pauses until payment is confirmed by the payment gateway. | Waits for a message, timer, or condition during the process. |
5 | Intermediate — Boundary Interrupting | Stock Not Available — an interrupting boundary event cancels packing if stock runs out mid-process. | Attached to an activity to interrupt it when triggered. |
6 | Intermediate — Boundary Non-Interrupting | Customer Inquiry Received — a non-interrupting boundary event logs a question from the customer without stopping packing. | Attached to an activity to handle side events without stopping it. |
7 | Intermediate — Throwing | Send Shipping Notification — actively sends a message when the order is shipped. | Throws (sends) a message, signal, or escalation during the process. |
8 | End — Standard | Order Delivered — the process ends once the customer receives the package. | Marks the normal completion of the process. |