Well now I come to think of it,
The number of times the process wil scheduled will either remain same or it will decrease, it will NEVER increase. However, the turn around time may increase of decrease given the scheduling pattern.
Case where it might increase
Initially time quanta 2
P1 needs 7 time quanta to finish and P2 and P3 needs 10. All arrives at 0
P1(2) P2(2) P3(2), P1(2) P2(2) P3(2), P1(2) P2(2) P3(2), P1(1), P2(2), P3(2), P2(2) P3(2)
TAT for P1= 19, P2 = 25, P3 = 27
Avg TAT = 23.6667
Increase the time quanta to 3
P1(3) P2(3) P3(3), P1(3) P2(3) P3(3), P1(1) P2(3) P3(3), P2(1), P3(1)
TAT for P1: 19, P2 = 26, P3 = 27
Avg TAT = 24