Do we need to assign the Story Points at the Story level or Task level ?

You don't need to assign story points any more than you need stories or tasks.

The Scrum Guide says:

At any point in time in a Sprint, the total work remaining in the Sprint Backlog can be summed

How do the team think they can best achieve this?

My opinion is that you don't need story points at all but know that many use them. So why are you using them and how does the team feel the activity will help them the best? 

Thanks Ian & Daniel for your inputs.

Regards,

Suresh Prabhu.

My 2 cents.  Story points for stories, hours for task.

To forecast number of stories per sprint, we add their total story points and compare with team velocity. 

Within sprint we track tasks by hours remaining thru burndown chart. 

If your stories are of same size, then you don't need to use story points.  Just count.

I hope our practice is correct per scrum.

I hope our practice is correct per scrum.

@Irma Irosido, Neither are necessary as per Scrum. Also, you may want to consider if you want to use both hours and points. Consider if that could be an unnecessary overhead

Irma, to add to Steve's observation, a task-based burndown chart can radiate healthy sprint progress even though stories are in an incomplete state and at risk.

You may find yourself at the end of a sprint where most of the identified tasks are finished, yet none of Sprint Backlog items (along with the Sprint Goal) are complete.   Measuring task completion actually detracts from the Scrum "goal" of item completion (meeting DoD).

Keep in mind that whether you use story points or task hours, these are both just estimates (guesses).   Therefore, there isn't really anything to be gained by substituting one type of estimate for another in a burndown view (SP/Velocity <=> Hours/Capacity)

Thanks for your insights.  Personally I like listing tasks as to-do list/ action items (based on DoD mostly)  and track completion.  But  I agree, updating hours in the tool is extra work but we manage. Once i finish task assigned to me i update done hours.  

The vibe I'm getting is not to practice Agile/Scrum for the sake of practicing Agile/Scrum but for the sake of delivering product of value.  I fully agree. 

Story points should be at Story level not Task level. "Story Points" name itself says.

Forget finding out where to apply these, you should find out what problem you're trying to solve by using Story Points. 

Are you using SP's because you're trying to put together a team's velocity? Ok Cool! Who's looking at the velocity? Is it being used for planning at the team level or is it being weaponized by management?

I suggest this reading:

https://medium.com/@matthewcroker/its-in-the-name-why-you-should-not-be-giving-story-points-to-anything-else-but-stories-49d1602b8436