How can I transition a parent issue once all of its subtask are in status "DONE"

Question

Hello I want transition my parent issue to a "complete" status after all of its sub task are done through automation.

So if issue "a" has 2 sub tasks

* sub task 1 - open
* sub task 2 - closed

& issue "b" has 3 sub tasks

* sub task 1 - closed
* sub task 2 - closed 
* sub task 3 - closed

Only issue "b" should transition to status complete.

I have tried issue conditions and jql conditions but I have ran into trouble. I am also open to scriptrunner if applicable. Please help.

Mikael Sandberg · Accepted Answer

If you look in the Automation library you will find a rule for this that looks like this

You can also find more templates here, https://www.atlassian.com/software/jira/automation-template-library#/