Gantt Charts: What They Are and How to Make Them

A Gantt chart is a key tool used in project management. Just like an architect creates a blueprint for a new project, a project manager makes Gantt charts to outline a project's roadmap. It's essentially a bar chart that conveys a project's timeline, tasks, and the team members associated with each task.

Gantt charts are used to help pinpoint realistic timelines and meet commitment deadlines. They also enable teams to visualize how much time and resources they'll need to complete a project, and can be used to communicate to stakeholders a project's timeline and how changes to project scope affect the outcome.

Learn more about Gantt charts, when and why to use them, and how to create them.

What is a Gantt chart?

A Gantt chart is a bar chart that visually depicts a project's timeline, tasks, and assigned team members. Project teams use Gantt charts to plan, schedule, and track projects, ensuring deadlines are met and resources are allocated effectively. It's one of the most popular project management tools.

In a Gantt chart, each horizontal bar represents a task, with the length corresponding to the time required to complete it. The bars are arranged on a progressive timeline, with each bar following the end of the previous bar. This is a technique also called the critical path method, where a project is broken up into tasks, and flexible schedules are determined for each task.

Project management tools like Jira or Wrike help users create Gantt charts efficiently. As a project manager, you can adjust information in real-time, map out project milestones, insert deliverables, and assign team members to specific tasks.

Brief history of Gantt charts

In the early 20th century, mechanical engineer Henry Gantt created charts to illustrate his production and manufacturing schedule. These Gantt charts helped monitor progress, thereby revolutionizing project management for projects as large as the Hoover Dam. At the time, engineers drew the charts by hand on paper, but the rise of computers in the 1980s allowed Gantt charts to be created on Excel and other project management software.

How to make a Gantt chart

In a Gantt chart, time is measured on the x-axis, while the work breakdown structure is laid out on the y-axis of the bar chart. New tasks can only start after the completion of a previous task.

By following these steps, you can create a Gantt chart that effectively communicates your project plan and helps you stay on track for successful completion.  

1. Outline the project scope.

To lay the groundwork for creating a Gantt chart, outline your project scope. Consider these elements:

• Goals

• Overall timeline

• Key dates

• Business case 

• Key deliverables

• Team 

• Resources

• Budget

• Schedule

• Risks

• Objectives and key results (OKRs)

• Approvals 

• Outcomes

2. Determine the task dependencies.

Research and talk with stakeholders to help you determine which tasks have the greatest priority. Then, define the relationships among tasks, which are called "task dependencies," and determine the order in which tasks should be carried out. At this point, you'll have the pieces you need to outline the Gantt chart.

3. Organize the individual tasks in chronological order.

With the tasks and dependencies in hand, organize them in chronological order. Estimate the time needed to complete each task and extend the task for the expected duration of time on the Gantt chart. You can consult with stakeholders for input on this step. 

4. Assign the tasks and availability.

The next step is to discuss team members' availability and develop a realistic timeline for the project’s goals. Assign tasks to team members, define their roles, and ensure teammates communicate any potential roadblocks. 

5. Monitor your progress.

The Gantt chart is a living document that you will likely need to update throughout the project's progress. It’s the project manager’s responsibility to monitor task progress and adjust the Gantt chart accordingly. 

Use the chart to track resources and deadlines. Monitoring progress maintains transparency and ensures tasks get completed in a timely manner. This process provides project managers with opportunities to learn valuable lessons for success in their next project.

Read more: How to Make a Project Plan in 4 Steps

How to make a Gantt chart in Excel

You can make Gantt charts in Microsoft Excel or Google Sheets. Take a look at this video for a step-by-step guide to creating a Gantt chart using the stacked bar method on Microsoft Excel.

Pros and cons of Gantt charts

Gantt charts are a helpful project management tool for visualizing your project's schedule, showing tasks, durations, and dependencies over time. Consider the following pros and cons of Gantt charts to help you decide when to use them.

Who uses Gantt charts?

Project managers use Gantt charts to monitor their team or client projects, but many other professionals benefit from using them. For example, event planners use Gantt charts to keep track of all necessary to-dos before an event, product managers often use Gantt charts to track the progress of product launches, and marketing teams use Gantt charts to meet a campaign's deliverables. 

Benefits of Gantt charts

• Visualization: Gantt charts offer a clear and easy-to-understand visual representation of the entire project. At a glance, you can see the timeline for each task, its dependencies on other tasks, and the overall project duration. This can be particularly helpful for complex projects with multiple tasks and dependencies.

• Improved planning: The process of creating a Gantt chart itself can be a valuable planning exercise. It forces you to break down the project into smaller tasks, estimate durations, and identify dependencies. This level of detail promotes better planning and reduces the risk of overlooking crucial steps.

• Progress Tracking: You can use Gantt charts to track project progress by monitoring the completion of tasks over time. They are flexible and can be adjusted as the project progresses, reflecting changes in scope, timelines, and resources.

• Resource Allocation: Gantt charts can help with resource allocation by visualizing which resources (people, equipment) are needed for each task and when. This helps avoid scheduling conflicts, overloading, and underutilization and ensures resources are used efficiently.

Limitations of Gantt charts

• Complexity: While good for visualizing simple projects, Gantt charts can become cluttered and difficult to interpret for complex projects with many tasks and dependencies. Creating and maintaining a Gantt chart can require a significant amount of time and expertise, which might be challenging for inexperienced users.

• Static nature: Gantt charts are not very flexible. Changes to the project scope or timeline require manual adjustments to the chart, which can be time-consuming and error-prone. They may not be as helpful in environments where requirements and priorities change frequently.

• Limited resource management: While Gantt charts can help with resource allocation, they don't offer advanced features for managing resource capacity or skills.

• Time-consuming: Creating a comprehensive Gantt chart at the beginning of a project can be a significant time investment that you'll need to plan for. If frequent changes in your project occur, you'll need to take time to update your Gantt chart. Using project management software can help streamline the process.

Learn project management

Want to start a career as a project manager? Consider enrolling in the Google Project Management Professional Certificate. No degree or experience is required. The certificate covers both traditional and Agile methodologies, including how to make Gantt charts, how to use project management software, and resources to get you started.