Chapter 18 of 185% of exam
Nevada Project Management & Scheduling
Managing a schedule means knowing which activities actually drive the completion date. This chapter covers the critical path and float.
The critical path
The critical path is the longest chain of dependent activities through the project network. Because no other path is longer, it fixes the earliest the project can finish, and every activity on it has zero float, so any slip on a critical activity delays the whole project day for day.
Float on non-critical work
Activities that are not on the critical path carry float - the amount of time they can slip before they would delay completion. Float equals the difference between the critical path's duration and that chain's duration, so knowing the float tells a manager which delays are absorbed and which are not.