In construction management, the float is the available time for which an activity be delayed without delaying the total project duration while working on the Critical Path Method for scheduling.
You can use the following formulae for finding float in general.
Float = Time Available – Time Required
There are majorly two types of float. They are:-
- Total Float
- Free Float
Total Float is the excess time available to an activity without affecting the project duration.
Total Float of an activity = Late Start time – Early Start Time or Late Finish Time – Early Finish time
Free Float is the excess time available to an activity without affecting the early start of the succeeding activity.
Free Float = Early Start – Early Finish
While most of the time these two types of float are extensively used, there are two other types they are
- Interferring Float – It is the amount of time available to an activity to delay its early start time, without affecting the project duration.
- Independent Float – it is the available time for which an activity can be delayed without affecting the early start of the succeding activity and the allowable delay of any precedding activity.