When using Primavera P6 Enterprise Project Portfolio Management (EPPM) to edit activity relationships, there are a number of different ways to do this. The most common way that schedulers make bulk relationship entries, is the using the relationship tab found in the bottom details area.
There is another way to define and edit activity relationships and that’s directly on the Gantt chart. Schedulers’ often find this handy feature useful when they want to update activity. Let’s take a closer look:
In Figure 1 above, we have our electrical construction project installing ‘Wellmont Substation’. Whilst reviewing our schedule we notice that the ‘Substantial Completion’ activity has five predecessors, making it a merge hotspot.
Merge hotspots are considered to be high risk because multiple predecessor activities have to complete before the successor activity can commence. The likelihood of all five predecessors finishing on schedule makes this merge hotspot activity a particularly high risk.
On closer inspection of these predecessor activities, a better relationship definition for the ‘Install Fence’ activity is revealed. By installing a perimeter fence around the construction site, the ‘bus and jumpers’, will be contained securely on-site without delaying the project. So, we now want to update ‘Install Fence’ and make its successor ‘Install Bus and Jumpers’, instead of ‘Substantial Completion.’ Here we show how to update the ‘Install Fence’ activity directly on the Gantt chart.
First, we need to remove the relationship which connects ‘Install Fence’ to ‘Substantial Completion’. By right-clicking on the relationship line between the ‘Install Fence’ and ‘Substantial Completion’ a relationship dialog box appears, which allows us to either ‘Edit Relationship’ or ‘Delete Relationship’, as above in Figure 2.
We select Edit Relationship which lists both the predecessor and successor this line connects too and we delete it, as in Figure 3 above.
Now we need to define a new relationship, connecting ‘Install Fence’ to a more suitable successor. We can do this by hovering the cursor over the end of ‘Install Fence’, and left-clicking as shown above in figure 4.
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’ as shown in Figure 5.
We make sure the cursor hovers over the white box on the predecessor side of ‘Install Bus and Jumpers.’ By hovering 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. As above in Figure 5.
Figure 6 now shows we now have an improved schedule with a Finish to Start (FS) relationship between ‘Install Fence’ and ‘Install Bus and Jumpers’. ‘Install Fence’ must complete before ‘Install Bus and Jumpers’ begins.
Only individual, one-to-one relationships are definable using the Gantt chart relationship edit method. But, all four relationship types are supported.
This Gantt chart method of edit activity relationships is another efficient feature that Primavera P6 Enterprise Project Portfolio Management (EPPM) supports. To draw each of these relationships on the Gantt chart:
- Finish to Start (FS) click from the right of the predecessor and drag to the left of the successor
- Finish to Finish (FF) click from the right of the predecessor and drag to the right of the successor
- Start to Finish (SF) click from the left of the predecessor and drag to the right of the successor
- Start to Start (SS) click from the left of the predecessor and drag to the left of the predecessor
As always with Primavera P6 EPPM, there’s normally more than one way to do things. This way to edit activity relationships directly on the Gantt chart is simply another method that most schedulers find useful.