Project progress management technology is made more objective by excluding as much human subjectivity as possible. Consideration is given to levels of importance of check items and tasks. A more accurate grasp of the progress of a project is enabled even if a significant change occurs in the middle of the project. An indication of a “complete” or “incomplete” state is used as a progress indicator of the lowest order tasks of the project, and progress of a high order task is based on the progress of the lowest order tasks.