Automation is a feature that facilitates automated changes to issues according to a set of criteria defined by an administrator.
There are three issue automation features available through the Settings Lightbox > Automation:
Auto Assignments
Auto assignment rules will automatically assign issues immediately upon submission to certain users or groups.
Workflows
Workflows provide the ability to update issues in a variety of ways after certain defined criteria are met.
Substatus Rules
Substatus Rules (if Substatuses are activated) will automatically change the Substatus field or pause the System Clock for an issue based on defined criteria.