When to use Tasks and Sub-Tasks

[Preem Prakassh Dayaal]

Hi All 

I have gone through a lot of posts around stories , tasks and sub-tasks and have had various views

Let me call out a simple situation 

 I have a user story : US001

Now this will have tasks such as Design, Devlopment , Testing 

Say my sprint is weekly and if I create 

Scenario 1 

Only two tasks out of three  and my US001 spills over to next sprint : in this case should I use tasks (link it to US001)  or sub-tasks within US001 ?

Scenario 2

If US001 can be completed within a sprint then is it preferrable to create 3 different sub-tasks and then complete it within a sprint ?

Will there be errors when I complete the sprint if all sub -tasks are not completed ? 

Please suggest when to use tasks and when to use sub-tasks ? 

Regards

Preem

[Nic Brough -Adaptavist-]

You are thinking of sub-tasks in the wrong way.  A sub-task is a part of an issue, it is not a separate entity.

The way to use them within Scrum is quite simple:

You create a load of stories, and take some of them into each sprint.  When the sprint ends, you might have stories that "spill over" - this indicates that your team has failed to deliver what it said it would for the sprint, and this is something that should be looked at to see how your team should improve (better estimation, not committing to more than it can deliver, misunderstood complexity, unidentified skills gaps, etc), or at least explained (resource loss to illness or emergency, etc).

A sub-task is a part of a story, created by the team to help them break up the story for some reason (different skill sets and hence people needed, different affected components of the product, different tasks within the story, reporting, logging time, developer likes breaking things up, does not really matter why).  They are not used to differentiate anything by sprint though.

The sub-task is not a sprint item, it's a part of its parent.  It moves through sprints with its parent.

[pranjal kohre]

It's confusing. Then what is the use of tasks?

[Nic Brough -Adaptavist-]

Again, a sub-task is a part of an issue, created by the team to help them break up the story for some reason while they work on it. 

[Stephen Dunham]

I understand subtasks as being part of a story.  But some of my team members are using Tasks instead of stories.  So as previously asked, what is the proper use of Tasks?  (how, when, by whom?).

[Nic Brough -Adaptavist-]

Welcome to the Atlassian Community!

It depends on what you are calling tasks.  Some Jira systems do not have issue types called "task" at all, some have them at the issue level, some have them at the sub-task level.

Tasks at the issue level are broadly the same as stories, tasks at the sub-task level are for what I described earlier.

[belinda pereira]

If a Task has 3 sub subtasks in a sprint, 2/3 are completed. Sprint ends. what happens to the incomplete sub task ? 

does it reflect in the sprint that 2/3 were DONE ? how does this look on the board? 

I understand one of the main issues with creating sub tasks in Jira is that is 1/3 is NOT DONE, and the sprint ENDS, this ticket remains open and get moved over to the next sprint. Is that correct or have I got it wrong ?