FCFS Rule:

The following flow time has been found with the FCFS based job sequencing rule:

Table: Flow Time of FCFS Based Sequencing

From the above analysis, total flow time may be easily calculated. Total flow time

= 220 + 570 + 745 + 990 = 2525 min.

Therefore, average flow time = 2525/4 = 631.25 min.

Now, compare the due date of the job with its flow time. From the comparison it has been found that Job (J1) and Job (J2) shall be on time, whereas, Job (J3) and Job (J4) shall become late by some amount of time.

Therefore, average lateness of the jobs = (0 + 0 + 355 + 370)/4 = 181.25 min.