Suppose I have this data:
| Step | Start | Stop |
| mixer | 0 | 2 |
| heater1 | 1 | 12.3 |
| injector1 | 4 | 4.5 |
| mixer | 6 | 8 |
| heater2 | 10.3 | 13 |
| injector1 | 12 | 12.5 |
| heater1 | 16 | 25.4 |
| mixer | 18 | 20 |
| heater2 | 23.4 | 30 |
| mixer | 24 | 26 |
| fan | 24 | 45 |
| mixer | 30 | 40 |
... and I want to make this plot (just the bars):

Is that possible with GraphBuilder? (note this image is a mockup with PowerPoint)