Critical Path Method – How to Calculate Float

There are two ways in which float of an activity can be calculated. But before that let me inform you that first step in critical path method is to identify the Critical Path of the Network. Once the critical path is identified, calculate the start date and end date of each of the activities on the critical path. As we have seen earlier, the float of the activities on the critical path is zeroso they represent the overall project duration. Now, that you know the Project duration. Either you can go through the network starting with time zero and keep on calculating the time required to complete each of the activity till you reach the last activity of the Project. This is also called Forward pass. The starting time for each of the activity in this approach is called Early Start and end time for each activity is called the Early Finish Or you can travel through the network from the project end date and calculate the time required to complete each activity. This is called backward pass. The end date in this approach is called the Late Finish and the start date of the activity in this approach is called the Late Start. The float of the activity is either the difference between the Early Start and Early finish or the difference between the Late Start and Late finish. Both the differences work out to be the same. If you are finding difficulty understanding critical path, I suggest that you go through the last two slides twice and than look at the next slide where in we have …