A task having multiple sub-tasks and few are completed in current sprint and rest to be moved

[PavanPalli]

I have task A which has 6 subtasks all are planned in sprint 1. Now 4 sub-tasks are completed and 2 subtasks are planned to take it up in next sprint. How do i move the subtasks to next sprint?

[Nic Brough -Adaptavist- · Accepted solution]

Sub-tasks are not sprint items themselves.  There's no such thing as "sub task in a sprint on its own".

Sub-tasks are part of a sprint when their parent issue is in it.  This is because a sub-task is part of its parent, not a separate entity.  

The 4 sub-tasks that are complete, great.  You've got two not complete, also fine.  This means the parent issue is not done.

So take task A into the next sprint to continue with it.  The 2 incomplete sub-tasks will then be part of the sprint because their parent is.

[PavanPalli]

Thanks for you response.

In this case how we calculate velocity? only 4 subtasks points to be considered?

[Nic Brough -Adaptavist-]

Velocity is a measure of what you commit to in a sprint vs what you achieve.

Sub-tasks are not sprint items, you don't commit to them, you commit to delivering their parents.

There's an essay on how to do sub-task estimates, but the outcome is

1. They do not directly count to velocity themselves.  If you do use estimates on sub-tasks, they only matter as part of the estimate of their parent

2. Jira does not natively have any support for any scheme for summing sub-tasks.  If you're going to do estimates on sub-tasks, you'll need to build/automate something.  Very carefully.

3.  Even if you do estimate sub-tasks, your velocity is still calculated on stories.

So, in the case you've got, you do no burndown until sprint 2, where, assuming all 6 sub-tasks are complete and then the story can be completed, you will burndown on the story estimate.