Before a new employee is created in PeopleSoft, it is critical that a search be done to ensure that employee does not already exist in the system.  This prevents duplicate ID's from being created, as well as a host of other potential problems.  For more information, refer to the guide "PeopleSoft Human Resources (HR3): New Hires & Job Data" starting on page 18.  Here is a link to the guide: PeopleSoft Human Resources (HR3): New Hires & Job Data