...
Within this system, I generally say each point is equal to half an hour of uninterrupted, focused work. So a quick favor for a colleague is 1 point, if you even document it at all (1- and 2- point tasks are usually created at the beginning of a campaign, not used for tasks an individual does on his or her own).
We try to keep tasks to a maximum of 13 points, as a 21-point tasks represents over a full day of uninterrupted work, which is both rare in work life and unfair to the assignee. If you see a 21-point task, see if it can be broken into more manageable tasks.
Assignee
This is the person responsible for completing the task.
...