Question

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

Answer 1

To create a Round Robin Gantt chart with the given processes and a time slice (quantum) of 40, we first need to understand the burst times of each process:

- P1 = 120
- P2 = 60
- P3 = 180
- P4 = 40
- P5 = 200
- P6 = 80

### Round Robin Scheduling Process

Using a time slice of 40, we will allocate CPU time to each process in a circular manner until all processes are finished.

#### Step-by-Step Execution:

1. **P1** executes for 40 (Remaining time = 120 - 40 = 80)
2. **P2** executes for 40 (Remaining time = 60 - 40 = 20)
3. **P3** executes for 40 (Remaining time = 180 - 40 = 140)
4. **P4** executes for 40 (Remaining time = 40 - 40 = 0, completed)
5. **P5** executes for 40 (Remaining time = 200 - 40 = 160)
6. **P6** executes for 40 (Remaining time = 80 - 40 = 40)

Now we repeat the process from the beginning:

7. **P1** executes for 40 (Remaining time = 80 - 40 = 40)
8. **P2** executes for 20 (Remaining time = 20 - 20 = 0, completed)
9. **P3** executes for 40 (Remaining time = 140 - 40 = 100)
10. **P5** executes for 40 (Remaining time = 160 - 40 = 120)
11. **P6** executes for 40 (Remaining time = 40 - 40 = 0, completed)

Now we repeat again:

12. **P1** executes for 40 (Remaining time = 40 - 40 = 0, completed)
13. **P3** executes for 40 (Remaining time = 100 - 40 = 60)
14. **P5** executes for 40 (Remaining time = 120 - 40 = 80)

Now we repeat once more:

15. **P3** executes for 40 (Remaining time = 60 - 40 = 20)
16. **P5** executes for 40 (Remaining time = 80 - 40 = 40)

Finally:

17. **P3** executes for 20 (Remaining time = 20 - 20 = 0, completed)
18. **P5** executes for 40 (Remaining time = 40 - 40 = 0, completed)

### Gantt Chart Representation

Putting this together, we can represent the Gantt chart as follows:

```
| P1 | P2 | P3 | P4 | P5 | P6 |
0 40 80 120 160 200 240

| P1 | P2 | P3 | P5 | P6 |
240 280 300 320 360

| P1 | P3 | P5 |
360 400 440

| P3 | P5 |
440 460

| P3 |
460 480
```

### Summary of Completion Times:

- **P1**: Completed at time 480
- **P2**: Completed at time 280
- **P3**: Completed at time 480
- **P4**: Completed at time 160
- **P5**: Completed at time 480
- **P6**: Completed at time 360

This Gantt chart captures the Round Robin scheduling of the processes given the time quantum of 40.