1) 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 on critical path has "zero free float", but an activity that has zero free float might not be on the critical path. Total float is associated with the path. If a project network chart/diagram has 4 non-critical paths then that project would have 4 total float values. The total float of a path is the combined free float values of all activities in a path.
The total float represents the schedule flexibility and can also be measured by subtracting early dates from late dates of path completion.[1] Float is core to critical path method.
Example
Consider the process of replacing a broken pane of glass in the window of your home. There are various component activities involved in the project as a whole; obtaining the glass and putty, installing the new glass, choosing the paint, obtaining a tin tty once it has set, wiping the new glass free of finger smears etc.
Some of these activities can run concurrently e.g. obtaining the glass, obtaining the