Childhood and Education
Henry Laurence Gantt was born on the cusp of the American Civil War in 1861 in Calvert County, Maryland. He became a teacher and a draftsman before becoming an engineer, and these three professions helped him form his theories on industrial productivity.
From 1887 to 1893 Gantt worked in technical management at Midvale Steel and Bethlehem Steel. It was only later that Gantt developed his famous work progress charts and the “task and bonus” method of determining pay for managers.
The Gantt Chart
Henry Laurence Gantt’s work was based on a philosophy that industrial output is ultimately a contribution of service to society, and he believed that managers should view their jobs as a form of public service.
The Gantt Chart is the distillation of many different versions of charts that plotted expected progress versus actual progress in a graphical representation of productivity and timeliness. It eventually evolved into its modern counterpart, the Program Evaluation and Review Technique, or PERT.
Though there were a number of variations on Gantt’s chart, the basic idea is to plot actual progress of a project versus expected progress over a period of time, commonly one year. Time is represented along the x-axis of the chart by the first letter of each month: JFMAMJJASOND.
A thin line running parallel to the x-axis represents expected progress on a project, and often, milestones are marked along this line. As the project progresses, a thick line is superimposed on top of the thin line, showing how far the project has progressed at any given time. For example, if it is June, and the thick line only reaches April, the project is behind schedule. Conversely, if it is June, and the thick line reaches all the way to August, the project is ahead of schedule.
Two of Gantt’s books, Work, Wages, and Profits, first published in 1916, and Organizing for Work, published in 1919, expand on his methods for maximizing productivity. In Work, Wages, and Profits, Gantt proposes giving the job foreman a daily “order of work,” (often called “work order” these days), and coordinating activities to avoid interference between tasks and those carrying them out. In Organizing for Work, Gantt discusses his two principles for charts:
- Measure project activities by the amount of time needed to complete them.
- Use the space on the chart to represent the amount of the activity that should have been done by that time.
Perhaps Gantt’s most lasting contribution to society was when his chart systems were used in major American infrastructure projects such as the Hoover Dam, which was begun in 1931, and the Interstate Highway network that was begun in 1956. It is a testament to Gantt’s practicalities that not only were these systems put into wide use after his death, but that they still exist and are used in modified forms even today, and have become “gold standards” of productivity tracking.
Gantt contributions to project management were so widely influential that in 1929, 10 years after his death, the American Society of Mechanical Engineers (ASME) established the Henry Laurence Gantt Medal, an annual honor that comes with a $1,000 prize.
So, if you’ve ever made a project timeline with filled triangles representing milestones, you’ve used the productivity method developed by Henry Laurence Gantt.