Applying Critical Path Method Analysis

Performing a Critical Path Method analysis on a project network diagram reveals the earliest and latest possible start and finish dates for each activity and the overall duration of the project. But what happens if the calculated dates don't fit within the project deadline? You can apply the results of your Critical Path Method analysis to help find the best way to reduce the overall duration of the project.
1) Crashing:

• Identify the critical path through the network diagram.
• Are there activities on the critical path that occur when no other work activities are being performed at the same time? Can the duration of these activities be reduced by applying more resources? What would be the cost of additional resources? Would reducing the duration of the activity result in cost savings such as reduced overhead or penalties? If the savings generated by applying more resources are greater than the cost and additional resources are available, the estimated duration can be reduced.
• Identify activities on the critical path that are performed simultaneously with activities that are not on the critical path. How much float, or slack time, is included in the noncritical path for the simultaneous activity? Can the duration of the activity on the critical path be reduced by the amount of float? What are the associated costs and savings? If the savings outweigh the costs, you may reduce the duration of the activity on the critical path.
• After you have identified all the available opportunities to shorten the critical path, perform a new Critical Path Method analysis using the revised duration for all activities. The critical path may change as a result of your revisions.

2) Fast-tracking:

• Identify the critical path through the network diagram.
• Reexamine the dependencies shown among activities on the critical path. Are there any activities that can begin before preceding activities have been completed? If so, the dependencies shown in the network diagram can change.
• Can the later activity begin at the same time as the earlier activity? Are there sufficient resources available to perform both activities simultaneously? If so, a parallel path may be created for the later activity. It can be moved off the critical path.
• Can the later activity begin after the earlier activity has begun but before it finishes? Are there sufficient resources available to perform both activities simultaneously? If so, revise the start date shown on the later activity. Using the estimated duration, recalculate the estimated finish date.
• When you have identified all the opportunities to fast-track activities on the critical path, perform a new Critical Path Method analysis of the project network diagram. The critical path may change as a result of fast-tracking.