"Mr. Gantt concentrated his attention on the development of a method of charting which would show a comparison between performance and promises... he had used a chart on which the work for machines was "laid out" according to the time required to do it. The Gantt Progress Chart, as developed from this early form, was found to help in the making of definite plans and to be highly effective in getting those plans executed. The rate at which the work goes forward is continuously compared with the advance of time, which induces action to accelerate or retard that rate. These charts are not static records of the past - they deal with the present and future and their only connection with the past is with respect to its effect upon the future."