A project-planning tool that can be used to represent the scheduling of tasks required to complete a project. Each task corresponds to a row. Dates run along the top of the chart in suitable increments of time. The expected time for each task is represented by a horizontal bar whose left end marks the expected beginning of the task and whose right end marks the expected completion date. As the project progresses, the chart is updated by filling in the bars to a length proportional to the fraction of work that has been accomplished on the task. Completed tasks lie to the left of the current date-line and are completely filled in. Current tasks cross the date-line and are behind schedule if their filled-in section is to the left of the line and ahead of schedule if the filled-in section stops to the right of the line. Future tasks lie completely to the right of the line. The chart was devised in 1917 by Henry L. Gantt, an American engineer and social scientist.