While a tutor is giving the diagnostic to one student the other students should sit and wait for their turn.
This is why we recommend doing the younger kids first , as they can have a tougher time sitting still, and diagnostics can be completed much quicker.
If there are any third grade students you can give them some written questions from the diagnostic sheet to start on while you do the oral diagnostics for the other students.
The diagnostic shouldn’t take more than a few minutes per student; especially for the younger students. Remember, you don’t have to go through the entire sheet for each student, just until they get stuck and maybe check a few similar modules of the inverse operation (if they are good for Add 0-5 to 0-5, and struggle with Add 6-9 to 0-5, still check Sub 0-5 to 0-5 and Sub 6-9 to 0-5).
Also, for the first class, the floating tutors should be helping with the diagnostics as well, which also speeds things up.
It’s possible the process might take longer than 30 minutes since it is everyone’s first time, but I think you will be surprised how quickly it goes.
Regardless, do not worry about timing, the 30 minutes is not a set time requirement, just what we usually see for the first class and we like to let the parents know so the first class is usually shorter so they do not wander too far.