When we give someone a task /action to perform we can leave it open ended. My wife gave me an action once (1993 I think), something to do with a mirror. I know I'm never going to do it unless I put a deadline in place, humans (most of them at least) function better when they have a deadline.
Actions need due dates - and if we have due dates then we need to be able to see when actions are overdue. That's the minimum - it would also probably be useful if people could get reminded as they approach these deadlines, and then maybe their boss could get a note when the due date passes – this is cruel and unusual punishment but it does help things along.
Tip #3 - Don't leave an open ended completion date