A Gantt chart is a type of bar chart that assists with visualizing or illustrating a project schedule. The chart is named after Henry Gantt (1861–1919), who designed his chart around the years 1910–1915.
This type of chart lists the tasks to be performed on the vertical axis, and time intervals on the horizontal axis.
The width of the horizontal bars in the graph shows the duration of each activity. These horizontal bars are the main design element of the Gantt Chart and assist with quickly communicating both the count, duration, and relationship (work done serially or in parallel) of the tasks. Gantt charts may be further illustrated with thin lines connecting the end of one bar with the beginning of another. These are used to signify dependencies.
Gantt charts can be used to show current schedule status using percent-complete shadings and a vertical "TODAY" line as shown here.
Gantt charts are usually created initially using an early start time approach, where each task is scheduled to start immediately when its prerequisites are complete. This method maximizes the float time available for all tasks.