1. In a data processing system associated with a plurality of users, wherein at least a portion of the users have each been previously assigned one or more permissions which correspond respectively to specified system resources, a method comprising the steps of: acquiring data from a first data source, wherein said first data source contains information pertaining to the users of said portion and to the permissions previously assigned thereto; acquiring data from a second data source, wherein said second data source contains information pertaining to one or more specified attributes of each user of said plurality; determining a set of permissions for a given role, wherein said set of permissions are determined using information from at least one of said first data source and said second data source, and said set of permissions comprises one or more specified permissions associated with resources of said system; determining a first criterion for assigning users to said given role from information contained in said first data source; determining a second criterion for assigning users to said given role from information contained in said second data source; and selecting a particular user for admission to said given role only if said particular user is in compliance with both said first criterion and said second criterion, wherein each user admitted to said given role is assigned each of the specified permissions of said permission set.