Question

Draw a Gantt chart that shows the completion times for each process
using shortest job next CPU scheduling with service times of 120, 60, 180, 50 and 300

Answer 1

While I can't directly draw images or Gantt charts, I can help you create one based on the data provided. Here's how to create the Gantt chart for your processes using the Shortest Job Next (SJN) scheduling.

### Given Job Service Times:
1. Job A: 120
2. Job B: 60
3. Job C: 180
4. Job D: 50
5. Job E: 300

### Step-by-Step Plan:
1. **Order the Jobs by Service Time**:
- Job D: 50
- Job B: 60
- Job A: 120
- Job C: 180
- Job E: 300

2. **Calculate Completion Times**:
- Completion time for Job D: 50 (0+50)
- Completion time for Job B: 110 (50+60)
- Completion time for Job A: 230 (110+120)
- Completion time for Job C: 410 (230+180)
- Completion time for Job E: 710 (410+300)

3. **Create a Gantt Chart Representation**:
```
|----D----|----B----|--------A--------|--------C--------|-----------E-----------|
0 50 110 230 410 710
```

### Summary of the Gantt Chart:

- **Job D** runs from time **0** to **50**.
- **Job B** runs from time **50** to **110**.
- **Job A** runs from time **110** to **230**.
- **Job C** runs from time **230** to **410**.
- **Job E** runs from time **410** to **710**.

You can now create a visual representation of this scheduling using a graphing tool or simply on paper, where each job is represented by its respective segment on the timeline.