The Gantt Chart is probably the most important contribution to the science of management made by Gantt. The fundamental principle of this chart will be understood from fig. 1, wherein it is assumed that 450 pieces of work are to be machined within a week of 45 working hours. This would mean an average of ten pieces per hour, so that, on this illustrative chart each horizontal space within a full day is taken as representing two hours of work ing time, also 20 pieces of work to be done. On Monday only 6o pieces were made, and the light horizontal line is accordingly drawn through three spaces to show the work done that day. Also a heavier horizontal, or totalizer, line is drawn below to the same length, or to the point (a). Tuesday 7o pieces were finished, and the light line in the Tuesday space is drawn through 31 horizontal spaces. At the same time the totalizer line is extended 31 spaces from (a) to (b) so that it then shows the completion of 13o pieces, or 5o pieces behind the schedule. Wednesday So pieces were done; the light line is drawn through the entire space for that day, and the heavy line still shows a shortage of 5o pieces, having been also extended through four spaces to (c). For each of the remaining days of the week the production was sufficiently above the schedule to complete the assigned task for the week. When ever the production runs above the schedule for the day the light line is drawn to the left the proper distance to show the excess, thus keeping it within its proper time space. In this manner, by means of very simple and easily drawn straight lines, there is available a daily picture of progress and accomplishment with relation to time ; and, at any time during the period, the total is clearly indicated.
Fig. 2 is a chart such as is actually used to keep a record of the hours that machines are operated and, when they fall short of the full working period, the reason for it. On this chart there is no Taylor believed that its benefits would continue to go to employers and workers as long as it was used. That is for the future to decide; but it has proved in application in many cases greatly to the advantage of both worker and employer and does much to keep the peace in industrial fields, pending further advances in our knowledge of how best to get from the earth's resources and equitably distribute the things needed for the support, comfort, progress and happiness of the human family.