Hi,
There is currently no way to have the subtasks completed when a task is marked complete. So I built a tool to, at least, be able to do this afterward, as a cleanup mechanism.
The rules are:
I hope that will be useful! iDO Tools - Improve Asana with our tools and automations
(Y)
Thank you for sharing this tool with us, Bastien. I just gave it a try and it worked like a charm. I use a lot of unassigned subtasks to depict our workflows and this will allow me to clean up projects after completion. Thank you!
Wonderful Jose 
i’ll share your quote on the product page if that is ok!
You my friend are a rockstar. This works great! Excited for the future tools that you build for Asana - invaluable.
tested it out and works great - but think is a use case for a feature that I have seen other users ask for (cause I was looking for it myself) - checklists.
similar to @JosePalomares I have tired using subtasks to catch those little details that are part of the process in getting something done - but the problem is you end up with a million tiny tasks, it really clutters up asana, makes reviewing tasks and projects messy, and add a whole layer of stress cause there are so many incomplete tasks.
thanks, Bastien, stress levels dropping - love your minimal website too!
@Bastien_Siebman would this work if the subtasks are assigned? We use sub-tasks to assign pieces of a larger task as many users do. However, some of those folks assigned to sub-tasks, complete their part and always forget to click the sub-task complete. Once our task is complete, we always have to look for unchecked sub-tasks. Would love to be able to check the task complete and any unchecked sub-tasks would be completed as well even if assigned.
@Martha_Hoffmann for safety reasons, I currently opted out assigned subtasks. But I’ll note to add this option!
This can be acheived for instance with a scenario built in Integromat.
Hi Bastien, some of my teams are asking for this “mark all subtasks of completed tasks as complete” rule, and I ran a diagnostic through your cool tool, but haven’t executed it just yet as I’m waiting to hear from my teammates if this is wanted.
Wondering if you ever made assigned subtasks as an option to be marked complete, too.
Definitely could, send me an email bastien@ido-clarity.com to discuss details.
Will the Subtasks Cleaner provide reporting as to how many parent tasks have incomplete subtasks? I do not want to auto-clean subtasks without first allowing my team to review their work and for me to analyze trends to identify why subtasks are not being completed by my team.
When you run the tool, the first step is to do a Simulation. You’ll get a full list of subtasks that will be cleaned.