Excel’s advantage is that if you’d like to make a change, for example altering the timespan or renaming a task, you can do this directly in the table, and the graphic will update automatically. If you’d like to introduce another task, though, you have to adapt the chart data area. As soon as you’ve activated the complete diagram with a mouse click, you’ll see the filter symbol. After clicking the button, you can then click on “Select data...” right at the bottom. In the menu that opens, you have the possibility to include data into your chart.
You can see the area currently selected in the top menu row. To add new tasks, you have to extend this. Write the correct cell references either directly in the cell or click on the button on the right edge of the row. You can now also select the area with the cursor.
In the course of a project, it’s also possible that certain tasks will come up again and again. To illustrate this, several bars have to be visible in the same row. First of all, add more columns to your table. Define additional starting points and timespans. Here, too, you have to adapt the chart data area and remove the coloring from the areas of the bars that aren’t relevant for your Gantt chart.