Definitions for "Critical task"
A task which is essential for accomplishment of the unit mission, successful individual skill performance, and/or survival in battle. It requires training and evaluation.
an individual task a Soldier must be trained on in order to accomplish their mission and duties, and to survive in the full range of Army operations
If the latest an activity can start is the earliest it must start, it is critical. Critical tasks show the same early and late dates on the forward pass as on the backward pass and in normally have no float.