In this example the machine should provide a serial number but it doesn't. This means the OT bus stop will update the highlighted work orders because:

1.     They have a matching order ID

2.     They have a matching operation ID

The Workcenter bus stop will find the two matching entries in the internal storage and will update both. It will also set the saga state of both to RUNNING (R).

This can be prevented by enabling the Mandatory property of the required tags in the channel message dialog.

If the required tags are set to Mandatory then, when a channel message is sent that doesn't contain all the mandatory tags, an error message will be generated and the message won't be processed.