Adding Event Diagram Elements to a BPM

Background

Diagram elements in a BPM fall into three types:

• Events: These initiate process transitions, such as Start or Signal Catch, and are integral to the BPM lifecycle.
• Gateways: They direct process flow based on conditions, acting as decision points within the BPM.
• Activities: Core elements that involve user interaction or system calls, representing steps like event calling or user tasks.

Figure 1 Diagram element types

Start

There are two start types for common start events:

• Custom: The event cause is not specified, that is, the trigger condition does not need to be specified. Generally, this is used for API start.
• Form: A BPM is started using forms or pages. If this option is selected, you need to configure a specific form, standard page, or advanced page.

Figure 2 Start Detail page

In the preceding figure:

• : indicates the page for configuring basic element information, including Label, Name, and Description.
• : indicates the context used to create variables, formulas, and struct variables required in a BPM.

Throw Signal

When the Throw Signal event is reached during BPM execution, the engine sends an event to the system. Then, the BPM execution continues along the subsequent route. The thrown signal can be subscribed to and processed by the Signal Catch event.

When using this element, you need to configure the specific event to be thrown, and configure event parameter in the Input Parameters area.

Figure 3 Event Configuration page of Throw Signal

• Event: Select the event to be sent.
• Partition Key: If a custom parameter is selected from the event as the partition key, events will be routed based on this key. Events with the same key will be routed to the same partition. If no key is specified, events will be randomly routed to different partitions, enhancing concurrent processing performance.
• Target/Source: Assign a value to a custom parameter of the event. That is, assign the value of Source to Target.

Timer Catch

When the Timer Catch event is reached during BPM execution, the BPM is interrupted. The engine creates a timer. After the timer is triggered, the event ends and the BPM execution continues along the subsequent route.

When using this element, you need to configure Base Time, Offset Time, and Offset Unit. The following figure shows an example in which the BPM execution continues along the subsequent route one day after the reference time.

Figure 4 Catch Event Detail page

Signal Catch

When the Signal Catch event is reached during the BPM execution, the BPM is interrupted. After the Throw Signal or the matched signal sent by APIs ends, the BPM execution continues along the subsequent route.

When using this element, you need to configure Event, Event Conditions, and Outputs.

Figure 5 Catch Event Detail page

End

The End event indicates that a process or branch ends naturally and no operation is performed. If a BPM has multiple branch routes being executed, the BPM instance ends when the last branch ends naturally.

Terminate

The Terminate event indicates that a BPM is forcibly terminated and no operation is performed. When a BPM has multiple branch routes being executed, the Terminate event terminates all the active tasks on these branches.