Solution FCFS     Solution of example by using the FCFS rules:

The FCFS sequence is simply A-B-C-D-E. The "flow time" in the system for this sequence measures the time each jobs depends waiting plus being processed.

 Job Sequence Processing Time Flow Time Due Date Delays A 6 6 8 0 B 2 8 6 2 C 8 16 18 0 D 3 19 15 4 E 9 28 23 5 28 77 11

The First Come First Serve rule results in the following measures of effectiveness: Average completion time   = total flow time / no. of jobs                                          = 77days / 5                                         = 15.4days Utilisation     = total processing time / total flow time                      = 28days / 77days                     = 36.4% Average no. of jobs   = total flow time / total processing time                                 = 77days / 28days                                 = 2.75 jobs Average job delays = total delays days / no. of jobs                                 = 11days / 5                                 = 2.2days Summary and Comments on the solution [Example with Demo Solution 1]     [FCFS]