Today I saw this 
I teach all my clients to use the Complete feature of Asana, and to not have a done state in custom fields; and I realized Asana has one built-in in their “native” custom fields.
If you use this, then Project Progress doesn’t work. Portfolios don’t make sense. Workload is useless… Don’t do this please 
Hi @Bastien_Siebman, thanks for reaching out! I understand, you are making a good point here, it’s essential to mark a task as complete once it’s done.
Custom fields let you add additional data to tasks in your Asana projects and allows individuals to have clarity on work happening across their Organization. For example, you can add the “Task Progress” field to several projects and then create reports by tasks marked as “Done” across different projects.
In order to ensure the task is always marked as complete once the Done field is selected, we recommend creating a Rule.
Thanks again for your feedback!
I agree with @Bastien_Siebman The only time I recommend using this is together with a rule that would mark it as complete when selecting done, but then you also need another rule to mark it as done when completed. So this option calls for two rules.
A great addition would be that ASana automatically add these two rules (even on Premium) the a project when this custom field is used and then have a toggle to disable the rules if needed. This will bring more clarity to work.
Sometimes is needed to track and differentiate Done and Closed.
A task can be done but still pending closure/validation/acceptance.
So it makes one wonder when to use the Completed tick.
@Bastien_Siebman I hear ya! I think this is a great practice for clarity on work. Specially when involving an assignment!
That said, I’ve found Asana to be so flexible that I often track more than just “tasks”. While the core unit of measure is a task, you can exploit the platform to do so much more. The more you gravitate from a task as a unit of measure, the more I see a place for “Complete” as Custom Field criteria.
Even if you only use tasks to measure who needs to complete what and when, wouldn’t this still be an acceptable Custom Field for a portfolio?
I love @Paul_Grobler’s idea of having interchangeable simple rules. Where a change to a column will complete a task or vice versa (through a checkbox to operate in reverse). This should totally be #productfeedback if it isn’t already!
My related question to this is how you indicate that a task was deemed no longer necessary to the project, but you still would like to know that the task was originally created. I’d love to see a “hide” or “no longer needed” type of attribute on a task. Those tasks would be hidden by default but could be seen with a “Show All” view/filter.
In my experience, I use the “Done” status because my Asana rep told me it’s okay. However, I mainly use it because it’s difficult / inconvenient to toggle between Completed tasks within a project and it’s hard to read the Completed tasks with the Teal font / blur.
I also don’t want to create a separate report to view Completed tasks. My suggestion would be to make it visibly easier to view Completed tasks and the date they were Completed within individual projects instead of having to toggle views or create custom reports…
Excellent points and I’ve generally settled on what @Bastien_Siebman suggested for these very reasons. I also generally try and encourage the rule that whoever opens a task closes it in which case @Juan_Diego’s suggestion comes into play, ‘done’ is different to ‘closed’.
When I do use the not started, in progress etc. I generally use sections rather than a custom field.
Agreed. I really like Asana generally, but the fact that marking a task “complete” basically sends it to another dimension so you have no idea where you are in the grand scheme of things (e.g. are we at 25%, 50%, what?), and can’t go back and review things to make sure you didn’t miss anything.
…Unless there is actually a way to view a list of all completed tasks, in which case this feature really needs to be made much easier to find. As it stands, once a task is marked “complete” it appears to vanish forever. 
@Anastasia_Olson, @Emily_Roman just happened to write about this recently, so maybe this helps:
Larry
I am with @Juan_Diego here. In many workflows, “Done” is not the final status, there may be a “Closed”, “Verified”, “Archived”, “Published”, etc. after it.
In the cases where “Done” is our final step, I encourage using a rule as per @Emily_Roman’s comment. Unfortunately, the rule to mark something automatically as Completed when reaching the final status (“Done” or otherwise) only works for tasks, not subtasks. I would love to see rules being applicable at the subtask level.
I do prefer using sections too but when a task is visible/shared in multiple projects it is much more simple to change the task progress with one common custom field rather than each project section.
Do common sections not work or can you not then filter/ group by section
Having common sections is fine and it is quite interesting if some of the team prefer Board view. Issue is when you move one task from a section to another you must do it foreach project even if sections name are the same.
Oh one task shared in many projects, gotcha. Yeah My use case is project planning across different teams to see capacity/task load
