When we shall use the schedule compression techniques?

We might be required to compress our schedule if our progress in delivering schedule activities is not in sync with our planning and project appears to be behind schedule.

We can utilize Crashing or Fast Tracking based on the Project situation, if we are going good on cost, we may pull in extra resources and crash our schedule.

Else, we may want to perform few of the identified activities in parallel by utilizing available resources, the same may add significant tisk to the project and PM need to monitor such activities very closely.