link vs. sub-task

[Michael Martinec]

What is the difference between creating a sub-task underneath a parent task vs. simply linking a task to a parent task? When use linking and when sub-tasks? What are the advantages/disadvantages of these two relationships?

Is a link automatically created when creating a sub-task? Can I also add a 'blocking' relationship to sub-tasks?

Do any of these relationship types interfer with one of the Agile project management tools Scum or Kanban?

Thanks for clarifying - I'm confused.

[Tanner Wortham]

Imagine an issue named "Create a pizza for Frank on 3/7/13". you might find such tasks as "gather the incredients" and "cook the pizza." you might also find another issue named "Create a pizza for Frank on 3/8/13." Those two pizzas for Frank would be linked. I hope that illustrates the difference between the two.

To your other questions:

• No, links are not auto-created for sub-tasks, but these sub-tasks are present on the screen of the parent issue.
• It's usually implied that if a sub-task isn't complete, the parent issue also isn't complete. Still, you can create relationships (by linking) between sub-tasks where one must be complete before the other can be started.
• Linking doesn't interfere with any functionality in JIRA unless you configure your instance to do so.

[Michael Martinec]

Thanks Tanner for the reply!

But could it also make sence to put tasks "gather the incredients" and "cook the pizza" etc as steps into the workflow and not create seperate sub-tasks? After all, they do happen after each other... But I think I understand the main features of tasks/sub-task vs links now.

Lets say the parent issues are more like "Create a pizza for Frank on 3/7/13" and "Create a hot sandwich for Frank on 3/8/13" to differentiate the two parent tasks more as in the situation I am facing (although they do have some things in common). If an issue comes up along like "salami gone bad" (buy new salami), would you assign this issue as sub-task or just link this issue to the parent as "blocker"?

Cheers

[Natalie Hobson]

Michael, I like to differentiate between sub-tasks and links (all functionality available aside), in that sub-tasks are small pieces of work necessary to complete a task which encompasses them, and linked issues are related to that work but don't necessarily cause any conflict or dependencies (although they *can*). Using this pizza/sandwhich anolgy further:

Make pizza for Frank (task)

Roll out dough (sub-task of above task)

Add sauce and cheese (sub-task of above task)

Buy sauce (task) - linked to Make pizza for Frank issue as a blocker; buying sauce is not actually a part of making the pizza for Frank, but is is separate thing that has to happen so the pizza can be made. Does this make sense? :)

[Deleted user]

Thank You

[James Porter]

all this is making me hungry. But it did answer the question I had - thanks

[Kritika Mohinta]

Good reply! I was wondering the same!

[Tyler Quillen]

What is the difference between creating a sub-task underneath a parent task vs. simply linking a task to a parent task?

Creating a sub-task under a parent will give it the relationship of parent-child. This has the child appear in the sub-task section within the story, it gives the child a parent link upwards in the hierarchy of a project, it allows you to easily invoke transitions on children/parent that may require more advanced techniques if it were a link, it allows you to easily grab specific sub-task types within the JQL functions when filtering by project, JIRA has automatic and helpful task management features when tasks are linked via the parent-child ideas.

Linking is a method of connecting multiple tasks that do not require an existing relationship by simply passing one of them a key. You will need to manually create links between items or create transitions that link for you and the automagic of some features by JIRA will not work with links. You can manually create networks of relations and designate the relation with the options JIRA has available (blocks, associated, etc.), and even search for those types of relationships via JQL. 

When to use linking and when sub-tasks?

Sub-task functionality really shines when you are breaking down something large into smaller chunks that are all very inter-related. It works seamlessly with estimates like story points, time estimates, or tasks percentage complete.

Linking really shines when you have complex tasks that are seemingly unrelated and can standalone, but you have miscellaneous threads that tie the items together. Linking also helps when you are using multiple projects to track a single effort.

You can use both while tracking a project, they are not mutually exclusive. 

What are the advantages/disadvantages of these two relationships?

Organization and how you search for things is going to differ pretty drastically. These can be mitigated by being clever of how you link or import things. The automatic linking of child-parent and the built in support by JIRA for sub-tasks is a huge advantage. Links work across projects and have unique identifies like blocking or associated, so that is neat.

Is a link automatically created when creating a sub-task?

Yes. 

Can I also add a 'blocking' relationship to sub-tasks?

Only if you have a plug in. Although, I don't see why you would want a sub-task to block its parent? The sub-task can be in progress, which means it's parent is in progress, not blocked. Or you can just block the sub-task by using a "Blocked" status, which can transition upwards easily.

Do any of these relationship types interfere with one of the Agile project management tools Scrum or Kanban?

They are unique ways of linking tasks and should have little to no affect on your production methodology. I prefer parent-child, because JIRA likes it more than links. But... Scrum means sprints, points, estimates, splitting up work; you should use tasks with sub-tasks here and linking tasks together when it makes sense. 

At the end of the day, sub-tasks are easier and have more support via JIRA. Links are manual, but have more flexibility. Why use one when you can do both?

[karl_hamilton]

Nice breakdown Tyler👏🏾👏🏾👏🏾

I just wish sub tasks and tasks had percentage complete and auto parent inheritance for parents of percentage complete and story points effort etc 

[Maela Aseglio]

Dear All

I cannot find how a task is linked to the subtask, the CUS number is sequential for both task and sub taskas and it does not show anywhere any link . could you please support me to filter the subtask and task in the filter page ? i cannot find the link between the two.

[Riccardo Zaniboni]

I have a further question. How do I link a task (not a sub-task) to a parent task? 

[Certus Port Automation]

I have the same question as you, because i am also doubting about using tasks or sub tasks in specific situations.

[Jerel Crosland]

I may be wrong because I'm relatively new to Jira, but as far as I can tell, that is another difference between subtasks and linking. With linking there is no hierarchy available, no way to indicate the top or master of your linked issues.