Before you start a new project, it helps to have a roadmap, some kind of clear overview of all the necessary steps and the order in which those steps need to occur. That's essentially what a Gantt chart is. It doesn't matter if the project is a personal one, like adding a deck to the back of your house, or a business one, like building a new website. You need to know
- when and where you're starting,
- all the steps along the way and how long they will take,
- who is responsible for each step,
- the order in which the steps need to occur, and
- when the project will be completed.
Gantt charts, named for the engineer and consultant Henry Gantt, who developed and used them in the 1910s, are a visualization of a project from start to finish. They are an extremely common type of productivity tool, and they're a key part of many project management services. In fact, the excellent TeamGantt service even takes its name from the charts. In this article, I explain what Gantt charts are, what they do, and how people use them, and provide five steps for getting started with them.
What Is a Gantt Chart?
"A Gantt chart is a visualization of the steps it takes for your project to be completed," explained Kayvon Ghaffari, lead program manager at LiquidPlanner, when I recently asked him to share some insight about getting started with Gantt charts. LiquidPlanner is an Editors Choice-winning project management and workplace collaboration app that emphasizes Gantt charts.
Ghaffari reminded me that a project is different from other types of work. "A project is a set of work that has a beginning and an end, and the fulfillment of creating that project is a set of tasks," he said. Gantt charts work for projects specifically, not for ongoing work. They're about helping you get from the beginning to the end, so it's important that there is an end.
Gantt charts read from left to right, top to bottom. (See the image above from TeamGantt.) The x-axis is time. The chart starts when the project kicks off and ends when the project is delivered. Running the length of the y-axis are tasks, although they're merely in a list. Their exact placement on the y-axis is irrelevant, although they tend to fall in chronological order.
"A task has three components: what it is, how long it's going to take, and who's going to do it," Ghaffari said. On a Gantt chart, each task is represented with a bar. The length of the bar shows how much time the task will take. Often task bars are color-coordinated, indicating which person or department is responsible for getting the task done. As to the "what," the task name generally appears on the bar or becomes visible when you click on it.
In addition to showing all the tasks for a project and how long they will take, Gantt charts show sequencing and dependency. In other words, they show the order in which tasks need to happen, and whether one thing must occur before another. Why is that so important?
What Do Gantt Charts Do?
"Gantt charts make it visually clear that you can't do everything at the same time," said Chris Savoie, Workfront's direct of product strategy. He used the example of building a tree house. You can buy the nails and the wood at the same time, but you must cut the wood before you nail it into the tree.
Gantt charts show dependencies between tasks, usually with something like a line connecting them.
Before joining Workfront (which, like LiquidPlanner, is a tool for workplace collaboration and project management), Savoie worked on some highly complex projects with United Space Alliance in conjunction with NASA's Johnson Space Center. He mentioned that while sequencing and dependencies are important for even simple projects, like building a treehouse, they are crucial for massive, years-long projects, like building the International Space Station.
Another thing that Gantt charts do is help organizations or project leads manage resources. "Just because a task exists doesn't mean there's a person who is free to do it," Ghaffari said.
With a Gantt chart, you can easily see when people or departments are scheduled to work on tasks versus when they are free. "You need to be able to account for people's schedules and how many hours there are in the day," he added. Gantt charts create an effective way to see time, tasks, and resources.
Getting Started With Gantt Charts
Once you have a high-level understanding of what Gantt charts are and why they're useful, you can start making them for your own projects. These five steps will help you start.
1. Choose a Template or Build One From Scratch Generally, when you start a new Gantt chart, you have the option of using a template or starting from scratch. Templates might come from an outside source, in the case of those provided by project management software, or they can come from a past project of your own.
One of the benefits of using your own previous work to create a template is that you can often learn a lot from what happened in the past. The template will provide information about not only the tasks and sequencing, but also whether any tasks took longer than expected.
2. Mark Your Milestones Most software for creating Gantt charts includes the ability to add milestones. A milestone is a marker that indicates a phase of a project is complete. For example, in building a website, locking down the wireframes is a typical milestone.
When building a Gantt chart from scratch, it's often helpful to plot all the milestones before adding any tasks. Listing all the milestones helps break down the project into smaller pieces, and those smaller pieces are easier to conceptualize than the whole project at once.
3. Add Tasks, Sequence Events, and Create Dependencies The next step is to add tasks, sequence events, and create dependencies. When adding tasks, be sure to look at historical reports or talk to the people who will complete the tasks to get accurate estimates for how long they should take.
When sequencing events, keep in mind that it is possible for multiple tasks to be performed at the same time, but not by the same person. In a website build, one person can work on wireframes while another person gathers sample content for the prototype. But the wireframe designer can't also create mood boards simultaneously.
Add dependencies only after you've listed all the tasks and put them in the right order, and be careful with them. "The thing that can really mess you up is if you go halfway into the Gantt chart and see that, say, task 12 is no longer dependent on task 5," said Savoie. He added that beginners should be extremely careful not to remove dependencies unless they're sure it's correct to do so, because getting them back is very difficult if they create a long chain of events.
4. Watch Your Resources "Tasks need to be in the right order, and then you need to control for who is available to complete those tasks," Ghaffari explained. As mentioned above, just because there's a task to do doesn't mean there's someone free to do it.
Ghaffari noted that his company's Gantt chart software doesn't allow for overbooking, meaning LiquidPlanner won't let you assign someone to a task if that person is already assigned to a different task at the same time.
Gantt charts help you see not only if a resource is overbooked, but what the consequences are on the rest of the project schedule when it's corrected.
5. Collaborate "It's really important that people understand that the Gantt chart isn't magic," said Ghaffari. "Just because you've planned something, doesn't mean it has anything to do with reality."
The way to make sure the Gantt chart is in tune with reality is through collaboration. Often, Gantt chart software is part of a larger project management or workplace collaboration package. Everyone on a team should have the ability to at least see the chart, if not update tasks and other information that feeds into it. That way, if an assignee finishes a task early, and she has the power to update her progress to mark the task complete and correct the estimated time, and by doing she may help other assignees to get their tasks done early, too. Or she might also flag herself as an available resource to help with some other task until her next scheduled assignment.
Ghaffari summarized the power of collaboration this way: "If the Gantt chart is in a vacuum, who knows if it's accurate? If it's collaborative, then there are checks built in, and it's more likely to reflect reality. That's where the value of the Gantt chart shines."
Don't Rely Too Much on Gantt Charts
Both Ghaffari and Savoie told me that they use Gantt charts for planning and to check in on a project, but they don't like to manage day-to-day work in it. "It's a plan, not an execution schedule, typically," said Savoie.
Savoie also noted that a beginner might not realize that people rarely, if ever, look at entire Gantt chart at once because they're typically huge. "You'd need a billboard to print it," he said.
According to Ghaffari, "Building the Gantt chart is not the end goal. It's a visualization of the task plan and sequencing. The Gantt chart helps people understand how the plan is going to work."
If you're interested in Gantt charts, you're probably also interested in project management in general. For some excellent addition tips for keeping your project on track, check out my 4 Tips for Getting Started With Project Management and also my advice on How to Improve Communication for Better Project Management.