Consider a cluster that schedules jobs by using the Round-Robin Strategy, which is implemented as a queue. In the table below, you can see the length and arrival of each job. Assume a quantum of 30 ms. New incoming jobs will initially be placed at the head of the queue.
Fill out the completion time for each job, as well as the order in which they are executed and calculate the average completion time. When calculating the average completion time, don't take into account the arrival time of the jobs, consider only the absolute completion time.
| Job | Length | Arrival |
|---|---|---|
| a | 106 | 0 |
| b | 55 | 25 |
| c | 51 | 45 |
| d | 30 | 80 |
What is the order of execution? List the job for each quantum it runs, even if it does not run for the full 30ms.
What is the average completion time?