Crashing is the process of adding more resources to an activity, so that it can be completed faster.
If, an activity ‘A’ can be completed in 10 days time, by deploying 1 resource to it, the same activity can be completed in 6 days time by deploying 2 resources to it.
In this case we say that;
- Normal cost is 10 person days (man days)
- Normal duration is 10 days
- Crash cost is 12 person days (2 persons worked for 6 days)
- Crash duration is 6 days
Here one natural question can be; ‘Why is the duration not ‘5’, when we double the resources from 1 to 2). Mathematically you are right, but in actual practice, the duration compression is not in proportion to the resources.
When projects get delayed, project managers use both crashing and fast tracking of the activities on the critical path.