Abstract: A personnel assignment system is connected to a project management system and a personnel management system The project management system retains information on tasks to which personnel have already been assigned as task data. Task data is associated with identification data of the assigned personnel. The identification data, which is also included in the personnel management system, is used as record retrieval keys. The personnel assignment system automatically extracts related assigned tasks from the identification data when changes occur in the personnel data, and automatically executes reassignment of replacements.