Total volume training thoughts plz

Hi all. I have tryd alots of deffrent reps an set but i saw this some were an thought id give it a go.
Am sure every1 knows wat total volume training is but il explane wat i am thinking.
Say am doing 3x10 on squat that adds up to 30 total reps. say i was squating 80kgs for 3x10 = 30rep this week an maybe next week if am tired or had a hard day at work i maybe wouldnt get the 3x10, last set maybe only hit 8reps=28 total reps. Instead of only giveing myself 3 set to get 30 reps il just keep going till i get all 30.
 
The only thing with that is when do you know when to add more weight, well i thought that i would give myself no more that 6 sets to get 30 total reps. So After 1 light warm up set on my 1st work set i could maybe get 11 reps rest 2 min, 2nd set maybe get 10rep then maybe on the 3rd il only get 8reps =29, but instead of stoping there rest another 2mins an go again, i would only need 1 reps to hit 30 but if i felt like it i could prob push out more lets say 7reps, that would add up to 36 total reps. So for that day it only took me 4 sets to get 30 reps or more so il add on 2.5kg an go again next week, if it took me more than 6 sets il keep that weight till i get 30 reps in 6 or less sets then add weight on.
 
I was going to try this with a PPL routine Deads,chins,DB row,DB curl. Bench,OHP,Dips,Skulls, Squats, Leg ext, Leg curls. The only worry that i have is would it be to much work,would i end up over training doing this, it means that i can lift more weight for 30reps than just 3x10 lol i hope thats clear bear with me am not the best at explaneing things. thanks

set a number of sets within which u want to achieve the desired number of reps, once u can do this then increase the weight. so (using your example) once u can do 3 x 10 with 80kg (30 reps over three sets) it is time to add more weight