Network Diagram Calculate Stack Float

How to identify and calculate free float.

Network diagram calculate stack float. In summary find the second longest sequence of activities in the network diagram. Using the following table i have calculated the slack value and drawn a network diagram. For the purpose of this blog post we will take the below example of project schedule network diagram to find out float total float free float using the early start early finish late start and late finish. A b e f 14 weeks is the critical path a b d f 10 weeks a c e f 12 weeks.

This is only calculated on the last activity on a path. Here you can see afloat can be a positive or negative number. What is total float total slack a. To calculate total project float begin at the start date and add the duration of each activity in each possible path through the network diagram including nonworking days from the resource calendars to determine the early project end date.

The four corners will be calculated starting with the es and ef via a forward pass then the lf and ls via a backward pass. It is an input. So you have a project float of 3 days. The longest path through the network is the critical path.

Example of network diagram. Finally the float is calculated which is an output of the network diagram. We will discuss negative float later in this post. Your calculated critical path activities on the schedule network diagram will take 22 days.

I have written this post assuming that you have the basic understanding of project schedule network diagrams and can use cpm concepts to solve small networks to determine the critical path. So the node with free float is always the activity right before the finishing activity for activity on arrow type of network diagram or the finish for activity on node type of network diagram. So es for task 5 is 14 days dependent on task 4 which is the longer task. The duration box is known prior to drawing the network diagram.

Draw a network diagram task 1 4 days task 2 5 days task 3 3 days task 4 7 days task 5 4 days 0 4 4 9 14 18 4 7 147 task 5 is dependent on task 2 and task 4 being complete. For forward pass calculate the early start es and early finish ef. The certification exam has a few questions on network diagram wherein they ask you to solve the schedule network and calculate the floats. Determine total float free float.