The horizontal axis of the diagram represents the project's time consumption divided into intervals (days, weeks, months or years) and the vertical axis represents the tasks that make up the project.

The Gantt chart can be used to:

• Provide an overview of project activities.
• Plan project activities.
• Help you plan when the various tasks must be carried out.
• Allocate resources.
• Communicate project activities.
• Coordinate and manage the project's activities.
• Monitor the development of the project's activities.

How to make a Gantt chart

1. Make a list of the necessary activities/tasks. For example, by means of brainstorming or mind mapping.
2. Create a draft of the Gantt chart. There may be insufficient resources to perform all activities at the same time. In addition, certain activities will require other activities to be completed first.
3. Determine dependencies and schedule activities. This ensures that when the planning changes, the activities will continue to be carried out in the correct order. Ensure that dependent activities do not start until the activities they depend on have finished.
   Try to limit the length of the project's critical path: The sequence of critical tasks from start to finish that take the longest to complete. It is also the shortest possible time in which the project can be completed. Note that the critical path may change from time to time as activities are completed ahead of or behind schedule. Don't overload resources and allow some leeway in the schedule in case of unforeseen events. However, critical tasks should not have leeway, as they are part of the critical path.
4. Calculate the number of man-hours for each activity.
5. Determine who will perform which activities and adjust the number of hours when necessary.
6. Calculate lead time.

Here you can download  gantt_-_template

Template of the Gantt chart in excel. 

Origin

Henry Laurence Gantt (1861-1919) was an engineer and management consultant, but is best known for developing the Gantt chart. The method was first presented in the book "Work, Wages and Profit" (1916).