A Gantt chart is a project tracking tool. Using one, you can keep track of the dependencies between tasks and chart the progress of your project. If, for example, a few tasks take longer than expected, you’ll be able to see the expected project timeline blowout straight away.
A Gantt chart tells you:
- The tasks required for the current project.
- How long you expect the project to take.
- How long you expect each task to take.
- When you expect each task to start.
- Any dependencies: in other words, any tasks that have to be completed before others can be started.
This type of chart has a few positive aspects in project management:
- Easy to understand.
- Each bar represents a single activity.
- Very easy to change the chart.
- Can be constructed with minimal data.
- Shows task progress vs date.
- Less complex than a CPM (Critical Path Method) or a PERT chart.
However, it also has a few negatives:
- Does NOT show interdependence of activities.
- The effects of starting a task earlier or later are not shown.
- No way to indicate variations in expected time to completion.
- No details of a task are listed.
- Cannot be used for predictive analysis.
Part of Your Arsenal
The key point to remember when it comes to the pros and cons of Gantt charts is that you shouldn’t be using them by themselves. They’re good for their purpose: tracking the progress of a project through charting task and phase completion. You’ll need other tools to build a full picture of how your project is progressing.
Gantt Chart Dependencies
Gantt charts have two basic types of dependency:
- Tasks reliant on the output from other tasks. For example, if you’re putting together an IKEA cabinet, you might need to fix the sides in place before hanging the doors.
- Tasks reliant on people who are assigned to other tasks. For example, a team of people building a house might need to wait until the painter is finished painting the outside of the house before they can start the ‘Paint kitchen walls’ task.
How to Construct a Gantt Chart
To put together your own Gantt chart:
- Start with a Gantt chart template. You can find one for Excel on the Microsoft website: Simple Gantt chart template.
- Break your project down into phases.
- Break each phase down into tasks.
- Assign each task to a person or small team.
- Set an estimated amount of time for the task.
- Note which tasks are dependent on others.
- List your project’s phases and tasks down the side of your chart.
- For each task, specify:
- Who’ll be doing the task (a person or a team).
- The expected start and end dates.
- Current progress on the task.
- Any dependencies on previous tasks.
- List the days or weeks of your project across the top of your chart.
- Block out the time period that each task is due to take up.
- Check that dependent tasks don’t overlap. In other words: if Task B needs the output from Task A, you can’t run them at the same time. Set Task B to start after Task A ends.
Points to keep in mind
Remember these details:
- You can have overlapping tasks, as long as those tasks don’t need the same resources or people, or need input from each other’s output.
- You will need to keep your Gantt chart up to date. Your team will rarely hit the target completion time dead on. They might finish tasks early or late.
- Many tasks will have more than one dependency. Particularly later in a project.
Online Gantt Chart Tools
A lot of companies offer cloud-based Gantt charts. One of the oldest of these is Microsoft Project, which has the advantage of integrating with other programs like Outlook and Excel. Newer options include Monday.com and Atlassian’s Jira.
Combine a Gantt chart with a project responsibility matrix to get a better overview of your project.