This is the documentation of JSU for Jira Server. If you are using JSU on Jira Cloud, you can find the documentation here.
The 'Transition Trigger Service' is available from JSU 2.0
Define all paremeters
In the following screen, you can configure the details of the transition trigger service.
Workflow conditions and validators might prevent to perform the transition.
See the details of the above screen shot. Often people forget (or are too lazy) to close all resolved issues. With the above configuration they will be automatically closed after 2 weeks.
Some of our customers are also using the transition trigger to schedule some automatic status change.
Consider a workflow with a status Ready and a status Executed. And a custom field 'Execution Date/Time'. We then use the following parameters:
To trigger on those issues the transition to the
Target status: Executed
In that transition you might for example use some Webhook to trigger an action on an external system.