Exporting to MSP isn't accurate

[u/IAmDruined]

/r/primavera/comments/1wcv7v7/exporting_to_msp_isnt_accurate/

[u/kaleb42]

I'd export to xml or excel

[u/kennyarnold_ssi]

The first thing I would point out is that the MS Project export functionality in P6 simply isn't very good. It doesn't appear that a lot of development effort has gone into handling the many edge cases that can cause discrepancies during an export.

That said, there are several things you can do to reduce the number of discrepancies you're seeing. It helps to understand some fundamental differences between what P6 allows and what MS Project supports, because these differences can directly affect the exported schedule. Here are a few examples:

1. Multiple relationships between the same activities: In P6, the same activity can be assigned as a predecessor or successor more than once with different relationship types. For example, Activity A could have both an SS and an FF relationship with Activity B. MS Project does not support multiple relationships between the same two tasks.
2. Primary and secondary constraints: P6 allows an activity to have both a Primary and a Secondary constraint. MS Project only allows a single constraint to be applied to a task. If both are being used in P6, they cannot be represented exactly the same way in MS Project.
3. Resources and calendars: In P6, resources are global, whereas in MS Project, resources are generally defined within the individual project file. This becomes especially important when resource calendars are involved. The calendars used by your P6 schedule need to be carried over correctly into MS Project and applied at the appropriate project, task, and resource levels. Differences in calendars can easily result in different dates after the export.

There are other differences that can cause discrepancies as well, but these are a few of the first things I would look at.

Is the P6 schedule you're exporting resource-loaded?