Model 4b - Transporting Process Variables via Messages

Goals of this lesson

Learn how to transport data (e. g. variables) between pools by using message flows

How-to

The BPMN allows transportation of explicit data by messages. We will now transfer a variable called "var1" from the upper pool to the lower pool by using the message flow between the activities "Send Data" and "Receive Data".

Figure 1: Model 4b - Transporting Process Variables via Messages / IYOPRO-Link

Approach

Select the activity "Initialise Data" and define a variable called "var1" with the value 1 in the expression property.
Now click the message flow.

You will notice that it also contains an Expression property.
Click the Edit button
Enter the variable's name "var1" to make the message flow transport this specific variable

Since the lower pool now also possesses the variable "var1", we will use it for the decision making at the branching exclusive gateway:

Upper edge condition: var1==1
Lower edge condition: var1==2

After simulating the model, you will notice that the activity "Evaluate to 2" has never been executed.