Products > PSOP > Documentation Why do I have to close Primavera before I run the PSOP leveler? If Primavera P3e is not closed before starting the PSOP leveler, and kept closed until after PSOP has exported the new schedule back to P3e, the project data can become corrupted. The problem is that changes made to a project in P3e are not immediately saved to the Primavera database. Primavera does not provide a way to programmatically read the schedule visible to the user, so PSOP reads directly out of the P3e database. As a result, any changes that are made to the project but not committed to the database will not be noticed by PSOP. After leveling, PSOP can push its schedule into the P3e database, but the schedule changes made by PSOP will not be visible in P3e until the user refreshes the data. If PSOP exported a schedule that does not correspond to the project visible in P3e, Primavera will try to merge the new data with the data visible to the user and this can cause data corruption. Data corruption can occur even when only small changes, such as changing the start time of a single activity, have occurred. Data corruption can be avoided by closing P3e prior to clicking 'Level' in PSOP and keeping it closed until the PSOP schedule has been exported back to P3e. If the following steps are followed it is not necessary to close P3e prior to running PSOP: Click commit changes on the P3e file menu before running PSOP. Export the PSOP schedule back to P3e after PSOP is done leveling. Click refresh data on the P3e file menu after the PSOP schedule has been successfully exported. Close PSOP. It is now safe to modify the project in P3e. Modifying the project prior to this step can cause data corruption. As it is easy to forget one of the steps in the above procedure, it is not recommended. Closing P3e while PSOP is running is the safest procedure. Similarly, it is important that no other users on the network have a copy of the project open while PSOP is running (more information...). Back to FAQ