Bar or Gantt charts (Henry Gantt - Bar chart inventor) are a visual technique for listing the project activities within a specified time frame. Each activity is identified with a start and duration. Bar charts will also depict when activities should start and finish. Gantt charts are used to show planning, progress to date and slippage against the baseline type information.This type of scheduling tool is used where more detail is required in the project plan.
Using the WBS for a project, Gantt charts can be summary or detail in nature.