Basic Facts About Gantt Charts: Their Graphical Ingredients

Posted by Ute Gillet on Aug 25, 2016 9:40:22 AM

It's been a while since I started my loose series of blog posts giving insights into the basic facts and features of Gantt charts by writing about why they are still popular today.

I'm quite sure that to some the actual nature and structure of these charts has become a bit vague over times, what with further developments and extending of application fields. So I considered clarifying the graphical ingredients of a Gantt chart in the first place. 

Possibly, you'll be surprised that the text is rather short. But first, as I'd like to clear the above mentioned vagueness, I'm going to keep my explanation as detailed as necessary and as concise as possible. Second, a structure as simple - yet effective - doesn't need much words to be explained. And third, when it comes to a visualization technique like a Gantt diagram, I rather prefer to work with images than with words.

Chart structure

A Gantt is a type of bar chart, displaying activities (tasks or operations) against time. It consists of three parts: table, time scale and graph.

Structure of Gantt charts


Basic facts about Gantt charts: The table

The table is usually positioned on the left and contains a list of the activities. Design and extent of information given in the table is totally up to the user: While the screenshot above shows a table with production orders grouped by state, it would also be possible to display ungrouped activities and, for example, only display the Start and End fields.

Time scale

Basic facts about Gantt charts: The time scale

The time scale is displayed at the top. Structure and time unit can be specified depending on the time-span the schedule is focused on, e.g. short-term scheduling on minute-basis, or long-term planning on a monthly basis.

For more information on the options to design a time-scale read our blog Meaningful time scale in Gantt Diagram.


Basic facts about Gantt charts: The graph

In the graph, positioned on the right, each activity is visualized by a bar, illustrating start and end date and duration of each activity by the bar’s position and length. 

Note that to draw a bar two bits of information are always needed: start and end date, start date and duration or end date or duration. 

Time- and resource-oriented visual planning 

Gantt charts are the ideal tool for visualizing all kinds of time and resource-oriented planning data.

Due to their structure, they offer clear overview of the activities

  • type
  • start and end date
  • duration
  • possible conflicts (“overlapping” activities)
And the whole project’s
  •  start and end date

To sum up, a Gantt chart lets you recognize at a glance which tasks (activities) have to be worked off

Your next steps

Taste for more basic facts ? Download our free ebook!

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Want to dig deeper? Have a look at how Gantt charts optimize deadlines

Topics: Visual Scheduling Fundamentals