Total Float (TF) is a measure of the amount of time an activity can be delayed without delaying the completion of the project. It is also known as slack or float time. It is calculated by subtracting the Early Start date from the Late Start date, or by subtracting the Early Finish date from the Late Finish date.
Total Float can be calculated using two methods: Forward Pass and Backward Pass. The Forward Pass method involves calculating the Early Start and Early Finish dates for each activity in the project network. The Backward Pass method involves calculating the Late Start and Late Finish dates for each activity in the project network.
Total Float is an important measure of project performance because it helps identify activities that are critical to meeting project deadlines. Activities with zero Total Float are considered critical activities, meaning any delay in these activities will cause a delay in the overall project completion. Knowing which activities are critical allows project managers to focus their attention on those activities and take corrective action if needed.