How can a task be reassigned?

Hello,
is there a way to reassign tasks?
Is it possible for a task to be reassigned to another user or another role either after a certain period of time by the system or manually by an admin?

The use case would be the following: A user takes too long for a task and the admin wants to assign it to another user (could be another role or manager of the original user, for example). Or the system does this automatically after a certain amount of time has passed.

Many thanks in advance

You can re-assign tasks in the Administrator Application (BPM->Tasks->Pending Tasks->View details->Assign).

However, apparently you can assign a task only to a user who is anyway in the group of potential performers of that task - not to a totally different user. 

Thank you very much, good to know that it is only possible for users who are in the group of potential performers anyway and not for totally different users.