In project management, float or slack is the amount of time that a task in a project network can be delayed without causing a delay to:
- subsequent tasks (free float)
- project completion date (total float)
An activity that has a total float equal to zero is said to be a 'critical activity', which means that a delay in the finish time of this activity will cause the entire project to be delayed by the same amount of time. A critical activity typically has free float equal to zero, but an activity that has zero free float may not be on the critical path.
