In Primavera P6 Enterprise Project Portfolio Management (EPPM), you can edit relationship lines directly on the Gantt chart. As with many features in Primavera P6, there’s more than one way to define and edit relationships. The most common method, typically used by schedulers for the bulk of schedule relationship entries, is the successor, predecessor, or relationship tab way.
These tabs are found in the bottom details area. Another way is to use the Gantt chart to define or edit relationship lines. This technique is helpful for making individual relationship definitions or edits directly on the Gantt chart. Schedulers may find this approach an efficient way to update activity relationships during the Gantt chart review process.
This article shows a Primavera P6 EPPM classic view quick tip to create or edit relationship lines using the Gantt chart.
Our demonstration P6 EPPM project is displayed in Figure 1, again, classic view.
Figure 1
This is an electrical construction project to install a substation. Note that the substantial completion activity has five predecessors. This makes substantial completion a merge hotspot. A merge hotspot is an activity where numerous predecessors come together.
Merge hotspots are high risk, because multiple predecessor activities have to successfully complete before commencement of the successor activity. The likelihood of all five predecessors finishing on schedule makes this merge hotspot activity a particularly high risk.
An inspection of these predecessors indicates that there is a better relationship definition for the install fence activity. Let’s say the bus and jumpers are hazardous equipment. If this is the situation then we would want to construct the fence before installation of the bus and jumpers. The construction site perimeter fence can, therefore, provide security and protection from this hazardous equipment. If this is the true situation then me must update install fence and make its successor install bus and jumpers, and not substantial completion.
So we want to update the install fence activity. We can proceed and update the install fence activity using the bottom details relationship tab method, Figure 2.
Figure 2
But since we are already examining the Gantt chart it might be more efficient to make this relationship update directly on the Gantt chart. Let’s update the install fence activity using the Gantt chart.
First, we want to remove the relationship connecting install fence to substantial completion. On the Gantt chart we right click on this relationship line, Figure 3, and a dialog appears providing two alternatives: 1) edit relationship or 2) delete relationship.
Figure 3
We choose to edit the relationship. The edit relationship dialog appears, which lists both the predecessor and successor this line connects, Figure 4.
Figure 4
We confirm that this is in fact the relationship we want to delete and select delete in the edit relationship dialog, again, Figure 4. Figure 5 displays the schedule after removing the install fence to substantial completion relationship.
Figure 5
So the Gantt chart edit relationship dialog can be used to delete an activity relationship.
Now we want to define a new relationship connecting install fence to a more suitable successor. In Figure 6 we hoover the cursor over the end of install fence, and left click.
Figure 6
Then holding down the left mouse button down we drag the relationship line from the end of install fence to the beginning of install bus and jumpers, Figure 7.
Figure 7
We make sure the cursor hoovers over the white box on the predecessor side of install bus and jumpers. If hoovering the cursor correctly, a dialog appears indicating that W1120 is the target activity. We confirm W1120 is the target activity and release the mouse button. The updated install fence relationship is displayed in Figure 8.
Figure 8
And the final schedule displays in Figure 9.
Figure 9
This improved schedule has a Finish to Start (FS) relationship between install fence and install bus and jumpers. Install fence must complete before installation bus and jumpers begins. We have thus have achieved a dual purpose: 1) install fence has a more appropriate successor and 2) we have reduced the substantial completion merge hotspot predecessors to four.
It is important to note that only individual one-to-one relationships are definable using the Gantt chart relationship edit method. But all four relationship types are possible. This includes: FS, Finish to Finish (FF), Start to Finish (SF), and Start to Start (SS) relationships. Draw each of these relationships on the Gantt chart as follows:
- FS – Click from the right of the predecessor and drag to the left of the successor.
- FF – Click from the right of the predecessor and drag to the right of the successor.
- SF – Click from the left of the predecessor and drag to the right of the successor.
- SS – Click from the left of the predecessor and drag to the left of the predecessor.
Summary
Again, there is more than one way to edit relationship lines in Primavera P6 EPPM. As the Gantt chart is at the heart and center of scheduling software schedulers may find the Gantt chart method of editing relationships particularly handy. So the Gantt chart method is an efficient way to edit individual FS, FF, SF, and SS relationships. And, provides the scheduler another convenient feature in their scheduling toolbox.