Can I prevent an item or sub-tasks from being moved to a particular column?

[Yossi Geretz]

Can I prevent an item or sub-tasks from being moved to a particular column if the time allocation has not been entered?

Thank you for your advice!

[Yossi Geretz · Accepted solution]

Actually, I implemented this as a Validator on the Workflow Transition. It works much more effectively, it blocks the transition with an error message. Since a parent item's calculated time spent is the sum of all its constituent sub-tasks, the parent item will have no problem making the transition after all of its sub-tasks have successfully transitioned.

If a value for field Σ Time Spent is not provided during the transition, show the following error: You must enter the time spent working on this sub-task..

[Yossi Geretz]

@Nic Brough -Adaptavist- I guess I must be on Classic, because I was able to do this as follows (screen-shot below).

However, the board doesn't update after this rule runs. If I refresh the page in the browser, I will see a non-compliant sub-task pop back into the In Progress column, but without that there is no indication that the rule has flagged the item as non-compliant. That's really only half of what I am trying to achieve. What I'm really trying to do is give the developer instant feedback to let them know that they are not compliant with our time tracking standards. This is going to be confusing when developers revisit the board hours later and just randomly find sub-tasks are not where they left them and they won't necessarily know why.

[Nic Brough -Adaptavist-]

Yes, if you are using classic projects.  Do you know if you are working in a classic or next-gen project?