5 The table lists activities which are involved in framing a picture. The table also lists their durations and their immediate predecessors. Except for activities C and H, each activity is undertaken by one person. Activities C and H require no people.
| Activity | Duration (mins) | Immediate predecessor(s) |
| A | select mounting | 5 | - |
| B | glue picture to mounting | 5 | A |
| C | allow mounting glue to dry | 20 | B |
| D | measure for frame | 5 | A |
| E | select type of frame | 10 | A |
| F | cut four frame pieces | 5 | D, E |
| G | pin and glue frame pieces together | 5 | F |
| H | allow frame glue to dry | 20 | G |
| I | cut and bevel glass | 30 | D |
| J | fit glass to frame | 5 | H, I |
| K | fit mounted picture to frame | 5 | C, J |
- Draw an activity on arc network for these activities.
- Mark on your diagram the early time and the late time for each event. Give the minimum completion time and the critical activities.
A picture is to be framed as quickly as possible. Two people are available to do the job.
- Produce a schedule to show how two people can complete the picture framing in the minimum time.
To reduce the completion time an instant glue is to be used. This will reduce the time for activities C and H to 0 minutes.
- Produce a schedule for two people to complete the framing in the new minimum completion time, and give that time.