Definition: A Gantt chart is a horizontal bar chart developed as a production
control tool in 1917 by Henry L. Gantt, an American engineer and social
scientist. Frequently used in project management, a Gantt chart provides a
graphical illustration of a schedule that helps to plan, coordinate, and track
specific tasks in a project
Gantt charts may be
simple versions created on graph paper or more complex automated versions
created using project management applications such as Microsoft Project or
Excel. |
A Gantt chart
is constructed with a horizontal axis representing the total time span of the
project, broken down into increments (for example, days, weeks, or months) and
a vertical axis representing the tasks that make up the project (for example,
if the project is outfitting your computer with new software, the major tasks
involved might be: conduct research, choose software, install software).
Horizontal bars of varying lengths represent the sequences, timing, and time
span for each task. Using the same example, you would put "conduct
research" at the top of the vertical axis and draw a bar on the graph that
represents the amount of time you expect to spend on the research, and then
enter the other tasks below the first one and representative bars at the points
in time when you expect to undertake them. The bar spans may overlap, as, for
example, you may conduct research and choose software during the same time span.
As the project progresses, secondary bars, arrowheads, or darkened bars may be
added to indicate completed tasks, or the portions of tasks that have been
completed. A vertical line is used to represent the report date.
Gantt charts
give a clear illustration of project status, but one problem with them is that
they don't indicate task dependencies - you cannot tell how one task falling
behind schedule affects other tasks. The PERT chart, another popular project
management charting method, is designed to do this. Automated Gantt charts
store more information about tasks, such as the individuals assigned to
specific tasks, and notes about the procedures. They also offer the benefit of
being easy to change, which is helpful. Charts may be adjusted frequently to
reflect the actual status of project tasks as, almost inevitably; they diverge
from the original plan.
