6 Sheona and Tim are making a short film. The activities involved, their durations and immediate predecessors are given in the table below.
| Activity | Duration (days) | Immediate predecessors | S | T |
| A | Planning | 2 | - | ✓ | ✓ |
| B | Write script | 1 | A | ✓ | |
| C | Choose locations | 1 | A | | ✓ |
| D | Casting | 0.5 | A | ✓ | |
| E | Rehearsals | 2 | B, D | ✓ | |
| F | Get permissions | 1 | C | | ✓ |
| G | First day filming | 1 | E, F | ✓ | |
| H | First day edits | 1 | G | | ✓ |
| I | Second day filming | 0.5 | G | ✓ | |
| J | Second day edits | 2 | H, I | | ✓ |
| K | Finishing | 1 | J | ✓ | ✓ |
- By using an activity network, find:
- the minimum project completion time
- the critical activities
- the float on each non-critical activity.
- Give two reasons why the filming may take longer than the minimum project completion time.
Each activity will involve either Sheona or Tim or both.
- The activities that Sheona will do are ticked in the S column.
- The activities that Tim will do are ticked in the T column.
- They will do the planning and finishing together.
- Some of the activities involve other people as well.
An additional restriction is that Sheona and Tim can each only do one activity at a time. - Explain why the minimum project completion is longer than in part (i) when this additional restriction is taken into account.
- The project must be completed in 14 days. Find:
(a) the longest break that either Sheona or Tim can take,
(b) the longest break that Sheona and Tim can take together,
(c) the float on each activity.