I create signpost tasks and assign arbitrary numbers to them (usually Fibonacci numbers). So maybe changing the label on a button is a 1 whereas adding a new per-user setting that needs to be stored on the server is a 3. I track my (or usually my team's) velocity over time, that is how many points we complete each sprint. After 3 or 4 sprints, we usually have enough data to know whether or not a particular group of tasks is doable in a single sprint. But I almost never know how long a single specific task will take. Sometimes it goes way faster and sometimes it goes way slower. That's why I usually commit to a group of tasks because the errors tend to cancel out.
I've found variations of that approach work on most teams I've been on. But really you've got to find the system that works for you and/or your team.
I create signpost tasks and assign arbitrary numbers to them (usually Fibonacci numbers). So maybe changing the label on a button is a 1 whereas adding a new per-user setting that needs to be stored on the server is a 3. I track my (or usually my team's) velocity over time, that is how many points we complete each sprint. After 3 or 4 sprints, we usually have enough data to know whether or not a particular group of tasks is doable in a single sprint. But I almost never know how long a single specific task will take. Sometimes it goes way faster and sometimes it goes way slower. That's why I usually commit to a group of tasks because the errors tend to cancel out.
I've found variations of that approach work on most teams I've been on. But really you've got to find the system that works for you and/or your team.
Did I miss something, isn't it CA Rally you are mentioning about?
Maybe so. I'm not familiar with CA Rally, but it might be the same thing.