Here are 13 questions on FCFS(FIRST COME FIRST SERVED) process scheduling algorithms, .Each question is presented in a table format, followed by the solution with Gantt charts, average turnaround time (TAT), and average waiting time (WT).
Question 11 :using the given table, find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?
| Process | Arrival Time (AT) | Burst Time (BT) |
|---|---|---|
| P1 | 0 | 3 |
| P2 | 2 | 6 |
| P3 | 4 | 4 |
| P4 | 6 | 5 |
| P5 | 8 | 2 |
| P6 | 9 | 7 |
Solution
Formulas :
Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)
Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)
Gantt Chart
| Process | Arrival Time (AT) | Burst Time (BT) | Completion Time (CT) | Turn Around Time (TAT) | Waiting Time (WT) |
|---|---|---|---|---|---|
| P1 | 0 | 3 | 3 | 3 | 0 |
| P2 | 2 | 6 | 9 | 7 | 1 |
| P3 | 4 | 4 | 13 | 9 | 5 |
| P4 | 6 | 5 | 18 | 12 | 7 |
| P5 | 8 | 2 | 20 | 12 | 10 |
| P6 | 9 | 7 | 27 | 18 | 11 |
Formulas:
- Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
- Average Waiting Time (Average WT) = Σ(WT) / Number of Processes
Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (3 + 7 + 9 + 12 + 12 + 18) / 6 = 61 / 6 = 10.17
Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 1 + 5 + 7 + 10 + 11) / 6 = 34 / 6 = 5.67
Question 12
find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?
| Process | Arrival Time (AT) | Burst Time (BT) |
|---|---|---|
| P1 | 0 | 5 |
| P2 | 1 | 9 |
| P3 | 2 | 6 |
| P4 | 3 | 7 |
| P5 | 5 | 4 |
| P6 | 6 | 3 |
Solution
Formulas :
Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)
Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)
Gantt Chart
| Process | Arrival Time (AT) | Burst Time (BT) | Completion Time (CT) | Turn Around Time (TAT) | Waiting Time (WT) |
|---|---|---|---|---|---|
| P1 | 0 | 5 | 5 | 5 | 0 |
| P2 | 1 | 9 | 14 | 13 | 4 |
| P3 | 2 | 6 | 20 | 18 | 12 |
| P4 | 3 | 7 | 27 | 24 | 17 |
| P5 | 5 | 4 | 31 | 26 | 22 |
| P6 | 6 | 3 | 34 | 28 | 25 |
Formulas:
- Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
- Average Waiting Time (Average WT) = Σ(WT) / Number of Processes
Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (5 + 13 + 18 + 24 + 26 + 28) / 6 = 114 / 6 = 19.00
Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 4 + 12 + 17 + 22 + 25) / 6 = 80 / 6 = 13.33
Problem 13
find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?
| Process | Arrival Time (AT) | Burst Time (BT) |
|---|---|---|
| P1 | 0 | 2 |
| P2 | 1 | 4 |
| P3 | 2 | 8 |
| P4 | 3 | 3 |
| P5 | 4 | 7 |
| P6 | 5 | 6 |
Solution
Formulas :
Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)
Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)
Gantt Chart
| Process | Arrival Time (AT) | Burst Time (BT) | Completion Time (CT) | Turn Around Time (TAT) | Waiting Time (WT) |
|---|---|---|---|---|---|
| P1 | 0 | 2 | 2 | 2 | 0 |
| P2 | 1 | 4 | 6 | 5 | 1 |
| P3 | 2 | 8 | 14 | 12 | 4 |
| P4 | 3 | 3 | 17 | 14 | 11 |
| P5 | 4 | 7 | 24 | 20 | 13 |
| P6 | 5 | 6 | 30 | 25 | 19 |
Formulas:
- Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
- Average Waiting Time (Average WT) = Σ(WT) / Number of Processes
Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (2 + 5 + 12 + 14 + 20 + 25) / 6 = 78 / 6 = 13.00
Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 1 + 4 + 11 + 13 + 19) / 6 = 48 / 6 = 8.00
Problem 14
find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?
| Process | Arrival Time (AT) | Burst Time (BT) |
|---|---|---|
| P1 | 0 | 6 |
| P2 | 1 | 3 |
| P3 | 2 | 5 |
| P4 | 3 | 7 |
| P5 | 5 | 4 |
| P6 | 6 | 2 |
Solution
Formulas :
Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)
Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)
Gantt Chart
| Process | Arrival Time (AT) | Burst Time (BT) | Completion Time (CT) | Turn Around Time (TAT) | Waiting Time (WT) |
|---|---|---|---|---|---|
| P1 | 0 | 6 | 6 | 6 | 0 |
| P2 | 1 | 3 | 9 | 8 | 5 |
| P3 | 2 | 5 | 14 | 12 | 7 |
| P4 | 3 | 7 | 21 | 18 | 11 |
| P5 | 5 | 4 | 25 | 20 | 16 |
| P6 | 6 | 2 | 27 | 21 | 19 |
Formulas:
- Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
- Average Waiting Time (Average WT) = Σ(WT) / Number of Processes
Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (6 + 8 + 12 + 18 + 20 + 21) / 6 = 85 / 6 = 14.17
Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 5 + 7 + 11 + 16 + 19) / 6 = 58 / 6 = 9.67
Problem 15
find the average Turn Around Time and Waiting Time of following processes using FCFS(FIRST COME FIRST SERVED) process scheduling algorithm?
| Process | Arrival Time (AT) | Burst Time (BT) |
|---|---|---|
| P1 | 0 | 7 |
| P2 | 2 | 2 |
| P3 | 4 | 6 |
| P4 | 6 | 5 |
| P5 | 8 | 3 |
| P6 | 10 | 8 |
Solution
Formulas :
Turn Around Time (TAT) = Completion Time (CT) - Arrival Time (AT)
Waiting Time (WT) = Turn Around Time (TAT) - Burst Time (BT)
Gantt Chart
| Process | Arrival Time (AT) | Burst Time (BT) | Completion Time (CT) | Turn Around Time (TAT) | Waiting Time (WT) |
|---|---|---|---|---|---|
| P1 | 0 | 7 | 7 | 7 | 0 |
| P2 | 2 | 2 | 9 | 7 | 5 |
| P3 | 4 | 6 | 15 | 11 | 5 |
| P4 | 6 | 5 | 20 | 14 | 9 |
| P5 | 8 | 3 | 23 | 15 | 12 |
| P6 | 10 | 8 | 31 | 21 | 13 |
Formulas:
- Average Turn Around Time (Average TAT) = Σ(TAT) / Number of Processes
- Average Waiting Time (Average WT) = Σ(WT) / Number of Processes
Average Turn Around Time (TAT) = (TAT1 + TAT2 + TAT3 + TAT4 + TAT5 + TAT6) / 6 = (7 + 7 + 11 + 14 + 15 + 21) / 6 = 75 / 6 = 12.50
Average Waiting Time (WT) = (WT1 + WT2 + WT3 + WT4 + WT5 + WT6) / 6 = (0 + 5 + 5 + 9 + 12 + 13) / 6 = 44 / 6 = 7.33