A complex project would normally encounter several delays and may surpass the budget allocated for it making a project very costly and which may lead to losses. While may Project techniques fail in solving these problems, there are two (2) tools which have proven to be effective. * Critical Path Method (CPM) * Program Evaluation and Review Technique (PERT)
Summary:
1. CPM is a technique used in projects with predictable activities and tasks e.g. Construction projects.
2. PERT is a technique used in projects with unpredictable tasks and activities e.g. Research and Development projects.
3. CPM is a deterministic project management tool while PERT is a probabilistic project management tool.
4. CPM normally has a single estimate time for the project completion, while PERT may have three estimates for the project completion.
5. CPM allows Project Management planners to determine which aspect of the project to sacrifice when a trade-off is required to complete the project, PERT does not.
The CPM Process: 1. List all activities required to complete the project (refer to WBS). 2. Determine the sequence of activities. 3. Draw a Network diagram. 4. Determine the time each activity will take to completion. 5. Determine the dependencies between the activities. 6. Determine the critical path. 7. Update the network diagram as the project progresses.
Example 1 – The Critical Path Method
Planting Flowers and Trees No. | Activity | Duration (mins.) | 1 | Organise Utilities | 10 | 2 | Dig holes | 10 | 3 | Buy trees | 15 | 4 | Buy flowers | 15 | 5 | Plant trees | 10 | 6 | Plant flowers | 10 | 7 | Buy edging | 15 | 8 | Install edging | 10 |
The main activities to complete this project are 1,2,5,6 and 8 this is our Critical Path.
Time taken to complete tasks with CPM – 1+2+3+5+6+8 = 50