Scrum is just the time-scheduling model that we need right now. Check out what it is: https://de.wikipedia.org/wiki/Scrum
Sprints are scheduled for once a week . Long term planing is done as follows: Every idea/problem/solution/implementation idea/implementation of draft is stuck into the back-log. Then it is assigned a date by which it needs to be finished.
A Burndown chart:
A RUP Chart (I hope it's the right one =D)
Allocation of workload:
On the week the sprint starts every single card that is needed for that particualr sprint is added to the sprint.
Thanks