There is an efficient way to remove activities from a schedule in Primavera P6 EPPM and it’s called dissolving activities. Here we take a look at how to do it.
In the process of planning a project schedulers have to make numerous changes to the planned schedule. Many times these changes involve deleting activities that no longer fit in with the current project situation. But deleting an activity also removes predecessor and successor relationships, and produces a discontinuity in the schedule. There is a way in Primavera P6 Enterprise Project Portfolio Management (EPPM), however, to remove an activity and bridge the gap in logic.
This article describes a quick tip in Primavera P6 EPPM on how to remove an activity and retain schedule logic using the dissolve feature to remove unwanted activities.
We have in Figure 1 our demonstration Primavera P6 EPPM schedule.
Figure 1
This is a pipe repair and improvement project. The project manager has decided to install pre-insulated piping, so the insulate piping activity is no longer required. We therefore need to remove insulate piping from the schedule.
Let’s first delete insulate piping and explore what happens. In Figure 2 we right click on insulate piping and select delete from the popup menu.
Figure 2
Figure 3 displays the schedule after deleting insulate piping.
Figure 3
Test piping at pressure now has one less successor. Note, in particular, that strike forms now has no successor. This creates a discontinuity. This discontinuity is quite evident when we recalculate the schedule, Figure 4.
Figure 4
Write quality assurance report now rests on the project start date, which is not our intention.
In Figure 5 we return to our original schedule that includes the insulate piping activity.
Figure 5
We right click on insulate piping and choose dissolve from the popup menu, Figure 5. This time when insulate piping is removed, Figure 6, the gap between strike forms and write quality assurance report is bridged with a Finish to Start (FS) relationship.
Figure 6
Also, note the inserted FS relationship between test piping at pressure and write quality assurance report, which makes sense. So we have succeeded in removing an activity and bridging the gap in logic to maintain a continuous critical path through the schedule.
Summary
Deleting activities in Primavera P6 Professional takes out the activity and any associated predecessor and successor relationships. This most likely results in a schedule discontinuity.
On the other hand, dissolving an activity removes the dissolved activity and joins the predecessor and successor activities to retain the schedule’s network logic. Dissolving an activity is, therefore, a more efficient way to discard unwanted activities from the schedule.