4.3.2 Critical Path Analysis (CPA)
Critical Path Analysis (CPA) or Critical Path Method (CPM) is part of a planning system called Network Analysis. CPA uses the arrow diagram in which
- A circle represents an event (or phase)
- The arrow points to the next event (or phase)
The Network Critical Path Analysis is used when the project is slightly more complex than able to be depicted by a simple straight line sequence. Multiple activities may lead off one action and the project may have many outcomes triggered by a sequence of parallel activities.
Identifying the critical paths helps ensure that resources are allocated to best effect. Crash action occurs when the critical path of a set duration has to be reduced. Sometimes customers will pay extra to have the time frame shortened. The Project manger then determines the appropriate crash action such as:
- Hiring extra labour
- Hiring extra equipment
- Working overtime (weekends)
- Working at night
- Using different technology
In order to reach the optimum cost-time solution, the first thing to do is to crash all the critical activities. When this is done, the original critical path becomes shorter (that is, a new critical path is established).