Microsoft Project

What Is a Gantt Chart and Why Is It Important?

Gantt charts are a project manager’s go-to tool but what are they exactly? Why do many people consider them essential for project management?

A Gantt chart is displayed in Microsoft Project’s default view and they’re the go-to tool for project managers everywhere but what is a Gantt chart exactly? Why do many people consider them essential for project management?

A Gantt chart is a visual representation of a project’s tasks over time. Additionally, it shows task dependencies, milestones, and assigned resources. In short, a Gantt chart provides all of the information project managers are most interested in – all in one place!

Gantt charts have been in use for over 100 years. According to Wikipedia, the Gantt chart was invented by Henry Laurence Gantt in the 1910’s. Henry Gantt was an American mechanical engineer and management consultant.

Over the years, these specialized charts have been utilized on major infrastructure projects including the Hoover Dam and America’s interstate highway system. As a result, Gantt charts have become an indispensable part of every project manager’s toolbox.

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What Does a Gantt Chart Represent?

Projects are complex. They involve managing large numbers of tasks, assigning work to dozens (or hundreds) of resources, and working with substantial budgets. These factors all need to be reflected in a Gantt chart.

A Gantt chart represents all of the essential project elements. It shows the project’s goals, along with a detailed breakdown of all tasks, dependencies, and assigned resources. After work begins, a Gantt chart can be used to analyze progress against the project’s approved budget and schedule.

Here is a list of elements commonly found in Gantt charts.

Project Summary Task

The project summary task represents the project’s entire duration. In Microsoft Project, the project summary task’s name is bold and identified as task 0. The line representing the project summary task in the Gantt chart is light grey.

Plan an Industry Conference is the project summary task in the screenshot (below).

Project Summary Task

Summary Tasks

Summary tasks represent task groupings or project phases. A summary task’s duration represents the combined duration for all tasks in that phase. The line representing a summary task is dark grey.

In this example, Topic Selection is a summary task.

Summary Task


A task is an activity that needs to be completed within an allotted time. When all of the tasks have been completed, the project is finished. Tasks are represented by blue bars in Microsoft Project’s Gantt chart view.


Milestones are used to mark a specific point in time, often the completion of a phase or other goal in a project. In Microsoft Project, milestones are tasks with a duration of 0. They’re represented by diamonds in the Gantt chart.

Milestone Task


Dependencies determine how tasks are scheduled. There are four types of dependencies:

  • Finish-to-Start (FS)
  • Start-to-Start (SS)
  • Finish-to-Finish (FF)
  • Start-to-Finish (SF)

The default dependency is Finish-to-Start. In the example (below) task 3, List potential topics for keynote and breakout session has to finish before task 4, Evaluate topics with planning committee can start.

Task Dependencies

What Are the Benefits of Using a Gantt Chart?

Using the elements described in the previous section helps you can create a comprehensive project plan. Building a task list with duration estimates, dependencies, and assigned resources helps you construct a detailed schedule.

A Gantt chart is valuable to project managers as a visualization and prioritization tool. It provides a clear overview of all schedule-related information in one place. It communicates everything that needs to be done and identifies assigned resources.

Let’s look at the benefits of using a Gantt chart in more detail.

Communication and Accountability

Distributing a detailed schedule helps everyone understand the work that needs to be done and visualize how the tasks fit together. The Gantt chart clearly identifies every task, indicates who is responsible, and documents the time allotted to each task.

Resource Utilization

Resource information can be displayed on a Gantt chart. Seeing which resources have been assigned to various tasks helps project managers monitor resource utilization – avoiding situations where a single resource may be assigned to multiple tasks at once.

Tracking Progress

Once work on a project is underway, a project manager can update the Gantt chart to indicate how much work has been completed. This is useful for comparing actual work with a baseline. Variances in can be highlighted, helping everyone understand whether or not the project is proceeding according to plan.

Are Gantt Charts Effective?

Gantt charts represent all schedule-related information in a single location – but does that solve all of your problems as a project manager? Will a Gantt chart help keep your projects on track?

Like any tool, a Gantt chart can be effective if you understand how to use it and you keep your project information up to date. Gantt charts help everyone connected to the project understand the schedule and how their contribution is critical to completing the project on time.

In the hands of an experienced project manager, Gantt charts can be an effective tool for communicating detailed information about the project’s schedule, tracking progress, and monitoring resource utilization.

Henry Gantt would be proud. : )

By Michael Belfry

Working as a full-time training consultant, Michael provides Microsoft Office courses to government and private sector clients throughout North America.