Recently Project schedules were imported into Primavera P6 from a client. These projects were in the planning phase of the Project lifecycle and durations were still being changed on various activities. An issue came up while changing Original Durations. Even though the Original Duration was changed for the activity, the At Completion Duration / RD was not. This first was noticed when the dates on the activity did not shift and the rolled-up OD for a phase did not reflect the new OD that was just entered.

The Issue

No Durations have been changed yet in this example below. As seen in the example Activity 55 OD / At Complete Duration / RD are the same at 10d.

However, after adjusting the OD to 30d we can see that Remaining Duration and At Complete Duration stayed at 10d and the dates still reflect a 10d Duration as well. Also, notice that the new 30d Duration for Activity 55 did not roll-up.


When importing Projects from MS Project to Primavera P6 default Project calculations may not be the same and issues like the one above can arise. To solve this particular issue navigate to Projects -> Project Details -> Calculations Tab. Once they are under the Activities section there is a checkbox named “Link Budget and At Completion for not started activities”, mark the checkbox. (Side note: Ensure the Project that you would like to change this Project Calculation on is OPEN or else this checkbox will be greyed out)

Note that Oracle defines this Project Calculation as: “When this option is checked, Budgeted or Planned, Remaining, and At Completion values are set to equal for not started activities. If you want to baseline or hold constant, the Budgeted or Planned values in your project plan while recording updates to Remaining or At Completion values, unmark the checkbox to turn off this option. When this option is off, Budgeted or Planned values for a Not Started activity are retained when you update its Remaining or At Completion values.”

At first glance, this Project Calculation may seem like it is just for budget purposes, but as defined above it does much more than that. This option is checked by default for Projects in Primavera P6, however it may be unchecked when importing a project from MS Project into P6.

As shown in the example above due to the Project Calculation check box being marked Original Duration is now linked to Remaining and At Complete Duration for all activities not started.