Question

Create a Round Robin Gantt chart with processes
P1 - 120
P2 - 60
P3 - 180
P4 - 40
P5 - 200
P6 - 80

Answer 1

To create a Round Robin Gantt chart, we need to know the time quantum. For this example, let's assume a time quantum of 50 time units.

We have the following processes and their burst times:
- P1: 120
- P2: 60
- P3: 180
- P4: 40
- P5: 200
- P6: 80

Now, let's simulate the Round Robin scheduling.

### Round Robin Scheduling Steps:

1. Start with the first process in the queue.
2. Allocate CPU time up to the time quantum or the remaining burst time for the process (whichever is smaller).
3. If the process has remaining burst time, put it at the end of the queue; if it finishes, remove it from the queue.
4. Repeat the process until all processes are completed.

### Gantt Chart Creation:

**Time Quantum**: 50

### Execution:

1. **P1** runs for 50 (Remaining: 70)
Gantt: | P1 |
2. **P2** runs for 50 (Remaining: 10)
Gantt: | P1 | P2 |
3. **P3** runs for 50 (Remaining: 130)
Gantt: | P1 | P2 | P3 |
4. **P4** runs for 40 (Remaining: 0 - completed)
Gantt: | P1 | P2 | P3 | P4 |
5. **P5** runs for 50 (Remaining: 150)
Gantt: | P1 | P2 | P3 | P4 | P5 |
6. **P6** runs for 50 (Remaining: 30)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 |

Now continue with the remaining processes:

7. **P1** runs for 50 (Remaining: 20)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 |
8. **P2** runs for 10 (Remaining: 0 - completed)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 |
9. **P3** runs for 50 (Remaining: 80)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 | P3 |
10. **P4** is completed, continues with P5, since it is a single cycle
11. **P5** runs for 50 (Remaining: 100)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 | P3 | P5 |
12. **P6** runs for 30 (Remaining: 0 - completed)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 | P3 | P5 | P6 |
13. **P1** runs for 20 (Remaining: 0 - completed)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 | P3 | P5 | P6 | P1 |

Now for P3 and P5, since they have remaining burst time left.

14. **P3** runs for 50 (Remaining: 30)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 | P3 | P5 | P6 | P1 | P3 |
15. **P5** runs for 50 (Remaining: 50)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 | P3 | P5 | P6 | P1 | P3 | P5 |

Continuing for final remaining from P3 and P5, final round:

16. **P3** runs for 30 (Remaining: 0 - completed)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 | P3 | P5 | P6 | P1 | P3 | P5 | P3 |

17. **P5** runs for 50 (Remaining: 0 - completed)
Gantt: | P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 | P3 | P5 | P6 | P1 | P3 | P5 | P3 | P5 |

### Final Gantt Chart
```
| P1 | P2 | P3 | P4 | P5 | P6 | P1 | P2 | P3 | P5 | P6 | P1 | P3 | P5 | P3 | P5 |
0 50 100 150 190 240 290 340 390 440 490 540 590 640 690 740 790 840
```

This Gantt chart shows the scheduling of processes in a Round Robin manner with the assumed quantum and executes until all processes are completed.