How does it work?

What Is a Gantt Chart

Projects involve a lot of moving parts.

There are tasks to complete, deadlines to meet, people to coordinate and dependencies that can affect when work can start or finish.

One of the most widely used ways to visualise all of this is a Gantt chart.

But what is a Gantt chart, how does it work and why do project managers use one?

In this guide, we explain what a Gantt chart is, what it is used for, how to create one, the benefits and limitations, and how Gantt charts fit into modern project management.

What Is a Gantt Chart?

A Gantt chart is a visual project management tool used to plan and schedule work over a period of time.

It displays project tasks against a timeline, making it easier to see:

• When tasks start
• When tasks are due to finish
• How long tasks are expected to take
• Which tasks are happening at the same time
• Which tasks depend on others
• How the project is progressing

A typical Gantt chart has a list of tasks on one side and a timeline on the other.

Each task is represented by a horizontal bar showing its planned duration.

This gives the project team a visual overview of the work from beginning to end.

What Does a Gantt Chart Look Like?

A simple Gantt chart might look something like this:

Task	Week 1	Week 2	Week 3	Week 4
Project planning	████
Research	████	████
Design		████	████
Development			████	████
Testing				████

The bars provide a quick visual representation of when each task is expected to happen.

More advanced Gantt charts can also show dependencies, milestones, task owners, progress and changes to the original schedule.

How Does a Gantt Chart Work?

A Gantt chart works by placing project activities against a timeline.

Each task is given a planned start date and end date. The chart then displays the task as a bar across the relevant period.

For example:

• Research: 1–10 October
• Design: 8–18 October
• Development: 16–30 October
• Testing: 28 October–5 November

When these dates are displayed visually, the team can see where tasks overlap and how activities connect.

This can make potential scheduling problems easier to identify.

What Is a Gantt Chart Used For?

Gantt charts are primarily used for project planning, scheduling and tracking.

They can help project teams:

• Plan project timelines
• Schedule tasks
• Set deadlines
• Understand dependencies
• Identify overlapping work
• Track project progress
• Coordinate teams
• Manage milestones
• Identify potential delays

They are particularly useful when a project has a defined sequence of activities or several teams need to coordinate their work.

Key Parts of a Gantt Chart

Although Gantt charts can vary significantly in complexity, most include several core elements.

Tasks

The task list contains the individual pieces of work that make up the project.

For example:

• Research requirements
• Create designs
• Develop the product
• Complete testing
• Launch

Breaking a project into clear tasks is an important part of project planning.

Timeline

The timeline shows when the project activities are scheduled to happen.

Depending on the project, the timeline could be displayed by:

• Days
• Weeks
• Months
• Quarters

Task Bars

Horizontal bars show the planned duration of each task.

A longer bar generally represents a task that will take more time, while a shorter bar represents a shorter activity.

Milestones

Milestones represent important points in the project.

Examples include:

• Project approval
• Design sign-off
• Development complete
• Testing complete
• Product launch

Milestones help teams understand whether the project is reaching its major stages as planned.

Dependencies

Dependencies show relationships between tasks.

For example, development may depend on design approval.

If the design is delayed, development may also be delayed.

Making these relationships visible can help project managers understand the potential impact of a delay.

Progress

Many modern Gantt charts allow teams to record how much of a task has been completed.

For example, a task might be:

• Not started
• 25% complete
• 50% complete
• 75% complete
• 100% complete

This allows the planned schedule to be compared with actual progress.

What Is a Gantt Chart Used for in Project Management?

Gantt charts are particularly useful for giving project managers a high-level view of project delivery.

Instead of looking at individual tasks separately, the team can see how the tasks fit together.

For example, a project manager might notice that three important activities are scheduled to happen during the same week.

If the same person is responsible for all three, there could be a resource problem.

The Gantt chart makes that potential conflict easier to spot.

This is one of the reasons Gantt charts remain popular in project management.

How to Create a Gantt Chart

Creating a Gantt chart does not need to be complicated.

1. Define the Project

Start by understanding what the project needs to achieve.

Clear objectives make it easier to determine what work needs to be included.

If you need help creating the wider project structure, our guide on what a project plan is and how to create one is a useful starting point.

2. Break the Project Into Tasks

List the work required to deliver the project.

Try to make tasks specific enough that someone can clearly understand what needs to be done.

For example, instead of:

“Website”

Use:

• Create page structure
• Write content
• Create designs
• Develop pages
• Complete testing

3. Estimate Task Durations

Decide how long each task is expected to take.

These do not have to be perfect estimates. The purpose is to create a realistic project schedule that can be reviewed and adjusted.

4. Add Start and End Dates

Give each task a planned start and finish date.

This creates the timeline that forms the basis of the Gantt chart.

5. Add Dependencies

Identify tasks that cannot begin until another activity is complete.

Dependencies are particularly important when building a project schedule because a delay in one task can affect several others.

6. Add Milestones

Identify the major points that matter to the project.

These milestones provide useful checkpoints throughout delivery.

7. Track Actual Progress

Once the project begins, compare actual progress with the original plan.

This is where a Gantt chart becomes more than a planning document.

It becomes a way of seeing whether the project is moving according to schedule.

Gantt Charts and Project Dependencies

One of the biggest benefits of a project Gantt chart is that it can make dependencies easier to understand.

Imagine a project with the following sequence:

Requirements → Design → Development → Testing → Launch

If requirements are delayed by five days, the impact may extend beyond that single task.

Design may start later.

Development may start later.

Testing may move.

The launch could potentially move as well.

Understanding these relationships helps project managers assess the consequences of changes to the schedule.

It also connects closely with keeping a project on track.

Gantt Charts and Project Planning

A Gantt chart is a useful visual representation of a project plan, but it should not replace the planning process itself.

A good project plan considers more than dates.

It may include:

• Project objectives
• Scope
• Tasks
• Resources
• Budget
• Risks
• Dependencies
• Stakeholders
• Milestones

The Gantt chart helps turn part of that information into a visual timeline.

For more on building the wider planning process, see our guide to project planning.

Advantages of Using a Gantt Chart

Easy to Visualise

A Gantt chart gives teams a visual representation of the project schedule.

This can be easier to understand than a long list of dates and tasks.

Makes Dependencies Visible

Teams can see how activities connect and identify tasks that could affect other work.

Helps With Scheduling

Seeing all activities on one timeline can make it easier to identify scheduling conflicts and overlapping work.

Supports Progress Tracking

Comparing planned dates with actual progress can help teams identify delays earlier.

Improves Communication

A visual project timeline can give stakeholders a shared view of what is happening and what is expected next.

Limitations of Gantt Charts

Gantt charts are useful, but they are not perfect.

They Can Become Complicated

Large projects can contain hundreds or thousands of tasks.

At that point, a Gantt chart can become difficult to read and maintain.

They Depend on Accurate Information

A Gantt chart is only as useful as the information behind it.

If dates, task progress or dependencies are not updated, the chart can quickly become out of date.

They Focus Heavily on Time

Gantt charts are particularly good at showing when work should happen.

They do not necessarily show the full strategic context behind that work.

A project can be perfectly on schedule and still fail to deliver the intended business outcome.

Plans Can Change

Projects rarely follow the original plan exactly.

New requirements, risks, resource changes and unexpected problems can all affect the schedule.

A Gantt chart therefore needs to be treated as a living project management tool rather than a document that is created once and forgotten.

Gantt Charts vs Other Project Management Tools

Different project management tools solve different problems.

Tool	What It Helps With
Gantt chart	Visualising schedules, timelines and dependencies
Kanban board	Managing workflow and work in progress
Task list	Organising individual activities
Project dashboard	Monitoring project performance and key information
Project report	Communicating progress, risks, issues and performance

These tools do not necessarily compete with one another.

Many project teams use several views depending on what they need to understand.

For example, a Gantt chart may be useful for understanding the timeline while a project dashboard provides a wider view of project performance.

Gantt Charts and Project Management Methodologies

Gantt charts can be used alongside different project management methodologies.

They are commonly associated with traditional or Waterfall project management, where work is planned in a sequence.

However, Gantt charts can also be used in Agile or hybrid environments when teams need to visualise larger timelines, milestones or dependencies.

The methodology determines how the team approaches the work.

The Gantt chart is simply one way of visualising part of that work.

You can learn more about different approaches in our guide to project management methodologies.

Can a Gantt Chart Replace Project Management Software?

A Gantt chart can be part of project management software, but a Gantt chart on its own is not a complete project management system.

Modern project management software may combine:

• Task management
• Gantt charts
• Project planning
• Resource management
• Risk tracking
• Project reporting
• Dashboards
• Collaboration
• Performance tracking

This creates a more complete picture of what is happening across the project.

The goal is not simply to know when work is happening.

Teams also need to understand what is happening, who is responsible, what is at risk and whether the work is delivering the intended outcome.

How CombinedWork Approaches Project Planning

Gantt charts are useful because they make project schedules visible.

But project management involves more than scheduling.

CombinedWork is a Project Management Operating System designed to connect strategy with execution.

That means the focus is not simply on creating a timeline.

It is about connecting:

• Strategy
• Projects
• Tasks
• People
• Risks
• Progress
• Reporting
• Business outcomes

A Gantt chart can tell you that a project is scheduled to finish on Friday.

The bigger question is whether the work is actually moving the project towards its objective.

That is the gap CombinedWork is designed to help teams understand.

Plan the work. Connect it to strategy. Track execution. See what needs attention.

Gantt Chart Checklist

When creating a Gantt chart, make sure you have:

• A clear project objective
• A defined list of tasks
• Realistic task durations
• Start and end dates
• Key milestones
• Task dependencies
• Task owners
• A way to track progress
• A process for reviewing and updating the schedule

Final Thoughts

So, what is a Gantt chart?

It is a visual project management tool that shows tasks against a timeline, helping teams plan, schedule and track project work.

Its biggest strength is visibility.

When project tasks, deadlines and dependencies are displayed together, it becomes easier to understand how the work fits together.

But a Gantt chart is only one part of effective project management.

Projects also need clear objectives, realistic plans, effective prioritisation, risk management and regular reporting.

The strongest project management approach connects all of these elements rather than treating them as separate pieces of work.

A timeline shows when the work should happen. Good project management helps you understand whether the right work is happening.

See how CombinedWork connects projects, people and strategy.