The ability to communicate is a definitive prerequisite for successful management of a project. Graphical displays such as gantt-charts usually make the information easy to identify; and thus are the prime means for tracking cost, schedule and performance.
Gantt-chart, being the most common type of display, is named after Henry Gantt, who first utilized this procedure in the early 1900s. The gantt-chart (or the bar chart) is a mean of displaying simple activities or events plotted against time. An activity represents the amount of work required to proceed from one point to another. Events are described as either the starting or ending point for either one or several activities.