In order to better see the total float of activities in your schedule, you may want to display the total float of activities on the Gantt chart.
It’s not uncommon that you have to consider options for delaying activities to move resources to, possibly, “crash” a critical path activity. Most likely, this request would come as a result of an active project’s status report update. So some of your activities, such as the start milestone, would already be completed. Thus, you only want to view on the Gantt chart the total float of activities that are not started or in progress, as it wouldn’t make sense to show the total float of a completed activity.
This article discusses how to use the Bars Form in Primavera P6 to set up a Total Float Bar that will logically display the total float of activities on the Gantt chart.
The “Null” Float Problem
Figure 1 displays an active project after four weeks of schedule updates.
Note the total float of activities in the Activities view. Also, note further that the completed activities have no float associated with them. They essentially have a “Null” total float value. Watch what happens when you activate the Float Bar in the Bars dialog, Figure 2.
First, you may want to make the total float bars more viewable by selecting a color, such as magenta, and making the bar a little thicker, again, Figure 2. When you click Apply after activating the Float Bar in the Bars dialog your Gantt chart will look similar to Figure 3.
Notice, in particular, how the default Float Bar assigns the completed Mobilize activity with float, in addition to both the start milestones, Figure 4.
This does not make logical sense, as you can see from the activities view that they have no float; their float value is “Null”.
To correct this issue we will have to adjust the Filter for the Float Bar in the Bars dialog, Figure 5.
Change the filter from ‘All Activities’ to ‘Not Started’ or ‘In Progress’, as displayed in Figure 6.
Also, make sure the ‘Show activities that match’ toggle is set to ‘Any selected filter’ that way it will display the total float for activities that are either ‘Not Started’ or ‘in Progress’. But not activities that are completed. After making the changes to the Float Bar filter as shown in Figure 6, your Gantt chart will look similar to Figure 7.
In Figure 7, only activities that are not started show total float. This is because for our example the one activity that is in progress happens to be on the critical path, so it has zero float. Now that your Gantt chart is displaying the total float of your not started and/or in progress activities you can see how Gantt chart total float visualization would help you better understand your projects total float.
Primavera P6 allows you to visually display the total float of all ‘Not Started’ or ‘In Progress’ activities. The one issue with the default settings is that they are also set to show total float for ‘’Null” activities, i.e. completed activities. This issue has a solution that simply requires adjusting the filter for the Float Bar from ‘All Activities’ to either ‘Not Started’ or ‘In Progress’ activities.
Once correctly implemented, displaying the total float of activities on the Gantt chart in P6 will visually show where and how much flexibility you have in the project schedule. This float tool is especially useful for large projects where you may have to readjust numerous resources scheduled to work on activities in parallel.