Arrival time, here, means the first time the process arrives in READY for this cpu burst.

Finish Time means the time the process finishes executing this cpu burst.

With these definitions, there is an easy relation between arrival, finish, and wait times for a given cpu burst:

        Finish = Arrival + Wait + CPU_Burst
     

or rewriting this for Wait:

        Wait = Finish - Arrival - CPU_Burst
     

Note that this is independent of which scheduling algorithm is used. That is, it applies to any of the scheduling algorithms whether they are preemptive or not.

Turnaround time for a given cpu burst can also be calculated this way:

        Turnaround = Finish - Arrival