How to you all set up tasks created by others and impact on capacity

So a strange question and back in the days of MS project i would have built these all by hand and has a massive time line…

Software / process project
Main task - Develop x
Do you all create tasks or sub task to allocated testing resource?
If these task then fails review how do you account for the new task, allocated ?

Clearly i am looking for Asana to pick up alot of the manual tasks.