Several of JSU's workflow modules provide the option the define the scope of the module on some related issues.
For example instead of copying a field within an issue during a post function, you might choose to copy it to a sub-task.

Types of Issue Relations

Related issue will be found by one of the following Jira concepts:

• Issue Link
  You can define the link type to define which issues exactly will be affected by the operation.
  If link type is  ANY, the operation will be performed on any linked issues.
• Parent / Sub-Task
  The related issue is either parent or sub-task of each other.
• Epic / Issue in Epic
   This is only applicable, if you have Jira Software installed.
  The other issue is either the epic related by an epic link, or it is part of an epic.

Issue in Transition

We use the term 'Issue in Transition' when we refer to the issue for which a workflow condition is checked, for which a workflow validator is examined, or for which a workflow post function is performed.

Or in other words that issue, which triggered a workflow condition / validator / post function to be executed.

Source and Destination

For example the Copy Value From Other Field Post-Function allows you to define the issue in transition as the source or destination of the copy operations, while you define the other end with an issue relation.
The field value will then be read from the source issue and be written to the destination issue.

Other workflow modules do not have source and destination. So you just define the issue relation, which will apply for that workflow module.
For example Create a Linked Issue Post-Function will just create a new issue and then connect it with some Issue Relation to the issue in transition.

Restrictions

Please use some common sense what can and what cannot work.

Some examples:

• Copy Value From Other Field Post-Function there should be only 1 source issue. Otherwise it is not clear from which the value will be read. (The current implementation will just pick one of them and ignore the rest. Which one is not defined - sort of random.)
• If you use Create a Linked Issue Post-Function to create a new sub-task, you must also configure this post function to create the new issue as an issue type of a sub-task and make sure the target project is the same as the one of the issue in transition.

We try to perform whatever is possible. In case of problems, the workflow module will still run through, but write a message into the log file. See Troubleshooting how to turn on the full logging for JSU. It might be a good idea to do this while you test any new workflow configuration to make sure you're not missing any thing.