It’s fairly easy to see what’s blocking actions when they’re delegated to a person. They can just be tagged @some-name.
But what about when an action is blocked by an event that may happen at an unspecified future date? (“we need to fix the transmogrifier, but can’t until the frobnicator we ordered online gets delivered” or “the plants should be brought indoors only after first frost of the season is forecast”).
When reviewing such tasks, I want to know at a glance what conditions to check before activating them, but that information doesn’t really seem to belong in the title; and if you put it there you have to edit the title when you activate the task, which is a little bit of extra friction.
‘Waiting for’ actions that block the actual task work well in this kind of situation.
Use a ‘Waiting’ tag to identify the events/deliverables you are waiting for. I prefer to give this tag the ‘on hold’ status, so that I don’t see those actions in all my perspectives of available tasks I can perform, and I check them as part of my regular review and planning. Other people prefer to make it an active tag, as you can see in other discussions on this forum.
You can put the waiting/conditional action as a child of the actual task, which will block it, or create a sequential action group, eg:
Fix the transmogrifier (Sequential; Complete with last action)
– Frobnicator delivered [Waiting]
– Fix the transmogrifier
