Example of Preemptive Task Scheduling Techniques

Example: Two processes with process IDs P1 & P2 with estimated completion time 8ms & 6ms respectively enters the ‘Ready’ queue together. A new process P3 with estimated completion time 7ms enters the 'Ready' queue after 5ms. Another new process P4 with estimated completion time 3ms enters the 'Ready' queue after 8ms. Calculate ‘waiting time’, ‘turn around time’ and ‘average’ of both timings using (i) SJF Technique (ii) RR technique considering the pre-defined time slot for each process is 2ms (iii) Priority based technique considering priorities P1=1, P2=0, P3=3, P4=2. Assume all the processes contain only CPU operation and no I/O operations are involved