Question

Draw a Gantt chart that shows the completion times for each process
using round robin CPU scheduling, with a time slice of 60.
p1|p2q|p3|p4|p5|
process 120|60|180|50|300|

Answer 1

Creating a Gantt chart requires simulating the round-robin scheduling for the given processes. In this case, we have the following processes with their respective burst times:

- **P1:** 120 ms
- **P2:** 60 ms
- **P3:** 180 ms
- **P4:** 50 ms
- **P5:** 300 ms

### Given Parameters:
- Time Slice (Quantum) = 60 ms

### Round Robin Scheduling:
The round-robin scheduling will execute the processes in the order they arrive, allowing each process to run for the time slice unless it completes earlier.

### Execution Steps:
1. **P1 runs from 0 - 60 ms** (60 ms used, 60 ms remaining)
2. **P2 runs from 60 - 120 ms** (60 ms used, completes)
3. **P3 runs from 120 - 180 ms** (60 ms used, 120 ms remaining)
4. **P4 runs from 180 - 210 ms** (50 ms used, completes)
5. **P5 runs from 210 - 270 ms** (60 ms used, 240 ms remaining)
6. **P1 runs from 270 - 330 ms** (60 ms used, completes)
7. **P3 runs from 330 - 390 ms** (60 ms used, 60 ms remaining)
8. **P5 runs from 390 - 450 ms** (60 ms used, 180 ms remaining)
9. **P3 runs from 450 - 510 ms** (60 ms used, completes)
10. **P5 runs from 510 - 570 ms** (60 ms used, 120 ms remaining)
11. **P5 runs from 570 - 630 ms** (60 ms used, 60 ms remaining)
12. **P5 runs from 630 - 690 ms** (60 ms used, completes)

### Completion Times:
- **P1:** Completed at 330 ms
- **P2:** Completed at 120 ms
- **P3:** Completed at 510 ms
- **P4:** Completed at 210 ms
- **P5:** Completed at 690 ms

### Gantt Chart:
```
| P1 | P2 | P3 | P4 | P5 | P1 | P3 | P5 | P3 | P5 | P5 | P5 |
0----60---120---180---210---270---330---390---450---510---570---630---690
```

This Gantt chart visually represents the order of process execution along with their respective completion times.