Is it possible to have a sub-task of a sub-task?

[Andrea Melde]

I would like to create a sub-task of a sub-task. Is there an add-on that will help?

[Fidel Castro]

No, it's not possible, but you can create a custom issue link type like "has subtask" / "is subtask of" and link your subtasks with it. This way you can build an parallel subtask hierarchy.

You can use "Condition / Validation on linked issues" and "Boolean condition / validator with math, date-time or text-string terms" of JIRA Workflow Toolbox to give consistency to this hierarchy and your workflows. For example, you can:

• Avoid symmetric "is subtask of" relations, i.e., IssueA is subtask of IssueB and IssueB is subtask of IssueA
• Prevent parent issue be resolved until all the subtasks have been resolved.