A critical path is an activity or event that, if delayed, will delay project completion. It is the chain of stages formative the least time needed for an operation, particularly when analyzed on a computer for a big organization.
Total Float: The total amount of time that a schedule activity may be delayed from its early start date without delaying the project finish date or violating a schedule constraint is known as total float. It is the amount of time an activity can be delayed without delaying the project completion date. On a critical path, the total float is zero. It is calculated by using the critical path method technique and determining the differences between the early finish dates and late finish dates.
It is obtained by deducting the early start and the activity duration from the Late finish of the activity. That means, we can get both the slacks obtained from the Late Start / Early Start, as well as from Late Finish / Early Finish. You can calculate the total float by subtracting the Early Start date of an activity from its Late Start date (Late Start date – Early Start date), or Early Finish date from its Late Finish date (Late Finish date – Early Finish date).
Thus, Total Float signifies the total slack time available for any activity in the Project without delaying the overall Projects duration.