Calculating duration percentage for the Oracle Primavera software can often times be a confusing and challenging process.
To make this easier to understand, we have broken down the basics and provided you with the formula in order to calculate the Duration percentages Complete for your project management processes.
How to Calculate Duration Percentage Complete for Oracle Primavera Software
Primavera P6 uses the following formula to calculate Duration % Complete:
Duration % Complete = ( [Original Duration] – [Remaining Duration] ) / [Original Duration]
This would return the expected Percentage Complete with respect to duration where the Duration at Complete or Current Duration is equal to the Original Duration.
At the time of updating a schedule, if the expected finish date of an activity results in the Duration at Completion being greater than or less than the Original Duration, the Original Duration remains as is and the Duration Percentage Complete remains as per the original calculation above.
Intuitively in these instances the Duration Percentage Complete can appear much less or greater than expected and becomes confusing when viewing the Gantt chart, graphically the current duration that has been actualized appears misrepresented as per the table below:
| Original Duration | Actual Duration | Remaining Duration | At complete Duration | Duration % Complete | |
| Scenario 1 | 100 | 80 | 20 | 100 | 20% |
| Scenario 2 | 120 | 20 | 100 | 120 | 0% |
| Scenario 3 | 100 | 20 | 30 | 50 | 70% |
Thus where one wishes to see a more ‘accurate ‘and less confusing reflection of the Duration Percentage Complete, it is necessary to change the Original Duration in order that the calculation performed by the P6 Formula For Duration Percentage Complete returns the desired result.
| Original Duration | Actual Duration | Remaining Duration | At complete Duration | Duration % Complete | |
| Scenario 1 | 100 | 20 | 80 | 100 | 20% |
| Scenario 2 | 120 | 20 | 100 | 120 | 17% |
| Scenario 3 | 50 | 20 | 30 | 50 | 40% |
This emphasizes the importance of having a baseline schedule against which the actual and forecast schedule can be measured and this will retain the Original Duration for reference if required.
The Duration Percentage Complete is not necessarily a reflection of the true percentage complete of an activity. If Duration Percentage Complete is not an accurate reflection of the activity status, then the Physical Percentage Complete needs to be calculated using predetermined weightings and entered manually. This automatically updates the Activity Percentage Complete for computing performance metrics such as Earned Value.
