3 Answers. Usually, estimation should be done in 2 levels at the start of each sprint: story level and task level. For best results, product owner and team should do both together, every time, although sometimes it is acceptable for the team estimate at task level without the product owner present.

When should estimation be used?

If a guess is totally random, an educated guess might be a bit closer. Estimation, or approximation, should give you an answer which is broadly correct, say to the nearest 10 or 100, if you are working with bigger numbers.

When should you estimate story points?

When to estimate story points

You need to assign story points to each story before you can organize the stories vertically into releases or sprints. That's because your team will have a limited timeframe to complete the stories assigned to each release, and usually two-weeks to complete a sprint.