Redmine

To clarify: the action would be: create a new issue that is related to this issue (e.g. it is related to the parent issue on creation)

Not much happening on this?

Mostly, in my experience, the relation is added after both issues exist.
Thus, I'd like to see it generally easier to find the related issue(s) when editing an issue.
Adding a bunch of related issues to a new issue is quite cumbersome presently (1.1.2). Some kind of search would be very useful.

Perhaps the "add parent" or "add related" could sport a search field that, when entered into, searches the issues of the current project (whole project tree?) and presents a kind of "dropdown list" (not a combo box) with the found issues. Kind of like the search suggestions google presents on the fly when writing in the search field. The desired issue(s) can then be clicked (multiple even).

Hm.. oops, it appears that the feature I commented about has already been implemented. And it truly rocks!
However, the '#' in front of the text input is a bit misleading, the user (read: I), thinks that a number is expected.

Anyway, good work!

How about just click on "new Subtask", cut the Parent Id, save new issue, add Related and paste the 'parent' id?