Gantt charts are not project plans

Sample Gantt chart

A critical component of the project is the project management plan. We’ve talked about developing a project management plan and schedule: Project planning – problems, scope, and deliverables, and Scheduling tips and techniques. There’s even a post on developing schedules so they display well on Gantt charts: Tips for developing a Gantt chart. Occasionally, there is a bit of confusion about what a Gantt chart is and how it can be used.

Gantt charts

The PMBOK, Fifth Edition, page 181, references Gantt charts in the context of the project schedule, “Bar charts are relatively easy to read, and are frequently used in management presentations.”

A Gantt chart is not a substitute for a project plan or a project schedule. It is a tool to help the project team understand the project schedule and visualize progress.  A Gantt chart is a product of the project plan and the schedule.

Keep in mind that in order for the Gantt chart to display properly:

• The predecessors and successors must be entered for each task.
• Ensure that any milestones that display are set to zero days.
• Tasks are assigned to the correct summary task.
• Summary tasks are not linked.

Want to know more? Here’s some great basic information on Gantt charts. The Ultimate Guide to Gantt Charts.

Great uses for a Gantt chart include:

Project visualization

Once you’ve developed the schedule, a Gantt chart is a great way to visualize the project. Show a high-level schedule and include progress if that helps your audience. The challenge with most projects is that it’s difficult to show the entire project via a Gantt chart.

If the project is more than about 20 lines, it’s difficult to display one page and make it readable.  You may need to make the Gantt chart a list of summary tasks only.

Summary tasks only

If you’re using software that can “roll-up” the tasks under the summary headings, developing a summary Gantt is a bit easier. It’s important when displaying a summary Gantt that the audience is aware that there are individual tasks in support of the summary tasks.

The challenge in showing just summary tasks is that summary tasks do not have predecessors or successors. Your chart shows lines across a page with no connections.

A Gantt for small projects

If you’re running a small project, it might be easier for the team to run using the Gantt chart. Depending on the software you’re using to develop your schedule, you might give each team member a Gantt chart of their activities, including the start and finish dates along with progress.

For many, a spreadsheet with lots of text is intimidating. Create a quick graphic and folks relax and actually read it. You’ll need to update it every week with progress. If you’re running a small project with only a few team members, this might be a good way to help them understand the project and the work.

Not the project plan

The Gantt chart is not a project plan. The project plan includes lots of information that the Gantt chart doesn’t relay, such as communication plans, risk strategies, and requirements management. The Gantt can display the schedule so that it’s a bit easier to understand and visualize, but it is only a picture of the schedule. Behind the scenes, a good project manager is updating and maintaining the schedule, then creating a new view.

How do you use Gantt charts? Let us know in the comments.

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